I will be following this question because I am in the same dilemma. It is time to replace our stairway and upstairs carpet and I have no idea what to use. Downstairs is all hardwood, but up is all carpet, and I can not afford to put hardwood upstairs. Our carpet is 22 years old, and looks it!

Wool is about $100 a square Yard and up, not per square foot. This may have been a typo on your part but I wanted to clarify.

What color is the dirt where you live? You will probably want to pick a carpet in a neutral color with the same undertone as the dirt/dust, so it could be a beige color with a slightly greyish, greenish or reddish undertone, for example.

Thanks palimpset. I guess I misheard the salesman. I live in NJ where the dirt is black.

Look into commercial carpet; many patterns; wears well; not cost prohibitive like wool.

Look for olefin or polypropylene as they are the most stain resistant. But don't get a berber as it will forever need cleaning. Look for a level loop commercial grade carpet in a tweed...it will hide almost all colors of dirt. If you go to a carpet store, they usually have books full of commercial grade carpets in tons of color combos.

They say there are 2 kinds of dirt....light dirt which is attracted to dark things and dark dirt which is attracted to light things.

I've found the same true of animal fur...

I am by no means an expert just a recent shopper myself... but I thought olefin or polypropylene are the least favorite types of carpet and SmartStrand or Anso nylon are the best regarding stain resistance & cleanability. Correct me if I'm mistaken, but if not, the OP may want to consider these two materials.

I was told by the carpet people that nylon is better wearing than polypropylene. And olefin is strong, but make sure it's not slippery.

Nylon is not colorfast and can stain. Olefin is made from polyolefin or polypropylene. From wikipedia:

"The fibers have low moisture absorption, but they can wick moisture and dry quickly. Olefin is abrasion, stain, sunlight, fire, and chemical resistant. It does not dye well, but has the advantage of being colorfast. Since Olefin has a low melting point, textiles can be thermally bonded. The fibers have the lowest static of all manufactured fibers and a medium luster. One of the most important properties of olefin is its strength. It keeps its strength in wet or dry conditions and is very resilient. "

It can be cleaned with mineral spirits or dilute bleach. It is used for indoor/outdoor carpet because of it's durability.

The problem with olefin is that it crushes. So if you buy it, get it in a dense pile or a low level loop. I've had olefin in my houses for years and the only one I had trouble with was the berber as it was light colored and with the crushing the traffic pattern was very apparent. Also, due to the low melt point, DH managed to melt part of the rug by putting a hot drop light on it. (If there's a way to destroy something, he'll find it!) I got rid of my nylon rug due to permanent stains it had (cat barfing up cat food...combination of food color with stomach acids caused awful color changes...we had the rug redyed by a professional, but that covered the spots only for a year or so.)

Just wanted to say I LOVE my smartstrand.

Any pets in the house?

No pets, but my kids (and okay my husband too) play a lot of sports and leave a lot of dirt on the carpet. Maybe I should tell everyone to take their shoes off at the door.

If you have basic DIY skills, I would recommend taking out all of the carpet and putting down hardwood floor.
Here is how to keep the cost down.
- Buy prefinished engineered hardwood flooring at lumber liq. sale.
- rent or buy a hardfloor nailer
- rent or buy an aircompressor
- rent of buy a chop saw
- bribe family, friends to help :)

We did part of our house using the steps listed above. Two people could do a bedroom in about one day.

Paid less than $3 per sq ft for indonesian solid cherry (prefinished) on sale. Looks new after 7 years! Easy to maintain.

I can only speak to having a dark carpet. If you go that route, make sure there is a pattern. We had a dark blue carpet (a long time ago) and I hated it, because you could see every piece of lint, crumb, etc.

In case this is helpful to anyone else considering wood or carpet, I stopped thinking about it as all or nothing ($3300 for carpet v. $7K for wood) and I think I will do the stairs and hallways wood (estimate is $1,100) and the 2 bedrooms carpet. DIY was an interesting suggestion but not doable with 2 full-time jobs and young kids.