Well, there are a bunch of possibilities:
1. Explain in detail how you will do the job and why it is superior to other "solutions." That way, the customer can ask any potential other bidders whether they use this superior way. If you know how others may do this on the cheap, explain what they may do and why the job should not be done that way. Of course, I don't know if there are too many possible short-cuts, but it would work if there's one or two cheap methods.
2. In many of these discussion threads here, some blame the customers when they are unhappy. They say, well, it's the customers fault when they expect the impossible with inferior material or natural materials, or whatever. I would say communication is key. You can't expect customers to have expert knowledge. So it is important to find out what they expect, what you can deliver and for what price. In fact, I'd advise fabricators to read the threads of unhappy customers very carefully and think how would I have addressed this.
3. There's always the possibility that a person wants a quick and cheap fix, just to sell a house, for example.

Honestly, I think there are customers around who are willing to pay for quality work, but it's up to you to explain what quality work entails. Also, it may help to offer a (longer) guarantee or warranty on your work.

This post was edited by nosoccermom on Sat, Nov 29, 14 at 10:55

Trebruchet, it may not be your sales skills. It may be a matter of what she can afford. She simply may not have had that additional 35% to spend, especially at holiday time. If she did not have the funds, she had to resort to the less-skilled contractor even if she knew very well that you are the better choice.

Or she just needs it fixed emough to sell the house and move on....

You're basing your assumption that your potential customer is at least half as smart as you. She may lack the mental comprehension to actually understand the technical differences, or the difference between cost and value.

One of my most priceless adventures lately was in the parking lot at the doctors when some young thing kept pointing the electronic key fob at her car and pushing the button. I offered to help, and proceeded to actually use the key to unlock the door. While she stood dumbfounded and confused. She probably still doesn't get it.

It may not be your skills - my in-laws would have gone for the cheaper option too, even if it's obviously inferior. They always go for the least expensive choice. They're cheap.

Well, I'm not sure I understood correctly. To me it sounded like you only found out about the cheap fix after the customer had made a decision. To what extent did you explain what you were going to do BEFORE she hired the other person? And did you explain that others may offer an inferior fix and what it may look like?
How is a non-expert supposed to know that the a sink installed with blocking and polyester is a non-approved method and guaranteed to fail? Again, sounds like some here are blaming, and insulting, the customer.

I have a parade of HVAC people marching through my house. Each one bangs the drum about the sheer incompetence of all the other HVAC contractors. This was installed wrong. That wasn't up to code. What were they thinking?

Not one has shown me a single piece of paper from a reputable independent source telling me what best practices actually are. They expect me to take their backstabbing and backbiting as gospel. Not going to happen.

It becomes an odd balance between the perception of a warranty, with no intent to honor and the integrity to having done the job with the intent that a warranty never need to be honored, ever.

The latter is to often perceived as ego, to the detriment of the pessimist.

For the last 30+ years I have been hearing how whoever was here before did not know what they were doing. I now perceive this as sales schtick. Of course, I have now learned there are a lot of contractors who do do poor work or do not follow specs or best practices, so we need to do our own research. But good luck getting anyone to follow directions or once underway and you see they've got their own ideas about things.

Me, too, shookums. Even after someone's hired, the previous person was a hack. In my case, given the 'good enough for not' methods my ex-GC-DH employed, they were right.

That said,
I think it's important to impress upon someone the apples-to-apples method. It's a given someone's going to shop. Often the 1st person gets the dream list, and the 3rd receives the pared-down, utilitarian, actually-possible list. Perhaps something with points against which shopper could check? Listing your warranty, which is worth gold against a WAG.

I'm not downplaying sales skills here. For example, "No" is a perfectly acceptable answer from or to anyone. But in your case, it sounds simply that it was price. Let her know you're available when the original, failing method fails again.

In my work we qualify corporate buyers as price, relationship, value or poker players (appearing to be one thing, but really another). The tactics and likelihood of success are different depending on where you sit in the relationship and what kind of buyer you're dealing with.

There are some people who will always buy on price. You let them go and move to the next opportunity, but are professional if they call you later after they engage in a bad deal.

Thanks everyone. I enjoy the different perspectives.

Do you have a website? If you do, I would post easy-to-follow explanations as to why some install practices are better than others. If you can get your clients to include how happy they are with your install...even better.

Some contractors come across as back-biting (as Marcolo said) or just plain condescending. Yes, they know more about the process...but every professional should know more about their business than their customer.

What's imperative is explaining the process to the potential client in a way that's not condescending, easy to understand, but still knowledgeable.

Hey, if it were easy...everyone would do it :)

Your photos and written explanations on GW of what you do and why have been excellent.

Have you thought of putting together an inexpensive photo book or two (Shutterfly, Snapfish, etc. all sell these) with play by play photos of problem sink installations with a brief, but thorough written explanation of why they failed, and how you go about repairing them? You might even get permission from some satisfied customers to include copies of thank you notes or quotes to include in the books.

Let's face it, most people are not knowledgeable about what's going on in the guts of their houses, let alone under their sinks. A little education of your customers could go a long way. If you had enough photo books, you could leave them with potential customers for a few days, possibly including some web links that they could use for their own research (I think I'd print these on separate business cards or papers since web addresses outdate themselves quickly. Vistaprint comes to mind for these.)

Customers would then have the chance to sit down and educate themselves without feeling any sales pressure. When you followed up with them a few days later, hopefully they'd return the books to you (getting them back could be tricky, I admit.)

Hopefully your satisfied customers are speaking good words about you. Word of mouth is the best advertising. : )

laughable:

If you're pressuring potentials right, they should never know. If I can't close the sale from my Laz-E-Boy, no Treb for you. These jobs are much too small for an on site estimate, think about it, and come back to do it.