I brought a sample home from Home Depot and could scratch it with my fingernail. Having said that, we went with a different brand as mentioned in my earlier post. it has a 5 mil wear layer with some kind of cerama beads, (I forget all the lingo I learned when researching ours). and I have never found a scratch on ours. We put it throughout our 1,000 sq ft cabin and also in our TV room at home. We have a 10+ lb. cat that tears around like a maniac. All claws intact. The wear layer is very important. It is recommended to put felt pads on all furniture feet. Makes for very easy moving of chairs etc. anyways. That way you shouldn't have to worry about scratches so long as there is no sand or stones lingering on the floor. But the felt pads would help minimize a problem anyways.

Our prior home had an open staircase - meaning no risers, just treads - so when we had the entire house repainted/replaced carpet and flooring and I wanted LVP in the front entry hall and stairs where before there was carpet, we didn’t have to worry about the risers too because there were none. However, after the flooring installers came and removed the carpet they stopped to call me on the phone and immediately advised we replace all the treads with new ones due to the majority having cracks across the entire width, the wrong kind of tread brackets on all of them, and to not replace would mean our stairs were too dangerous to do not just the stairs but the loft bedroom second floor carpet plus LVP in the bathroom. There was too much liability risk for them to allow a roll of carpet to get dragged upstairs potentially endangering their workers. So we had them replace the treads and brackets, then complete the rest of the job. Of course this was a home built in a SoCal gated HOA back in 1978, with no grass but ‘waterscaped’ ponds and streams instead. When I bought the place in 2002 the whole community had to be termite tented about 4 months after I moved in, and the fact that at least 3 of the treads in worst condition hadn’t completely failed before the replacement was a miracle from heaven. It was a disaster waiting to happen going up and downstairs! Whether or not your stairs are in similar condition to what we had experienced, I don’t know. But the pictures don’t show any truly noticeable ‘flaws’. Even if the treads did have problems, the time to have that addressed is when the flooring business/installer comes in to consult and put together a contract for what’s being done. If they don’t see a reason/indicate a reason to the customer regarding to replacing treads, it may be because they’re fine or may be due to trying to avoid submitting a bid that takes them out of the running for the job because it’s too high. So if the look your stairs have now is so problematic you want them to redo the work, you will have to pay for the materials (again, can’t really reuse) and the labor (again, because businesses can’t afford to eat the cost of paying for their workers to do a replacement for free when those workers could be sent to another job that keeps the business in the black and remain in operation down the road).

All the grout lines need to be filled and the floor flat to within 1/8" over 10'. Vinyl loves to telegraph every imperfection and those grout joints will do that in short order.

If these are VASTLY different costs, such as $3/sf vs. $8/sf, then the difference is the PREPARATION was mention in the $8/sf. In my neck of the woods (Canada, expensive city like Vancouver, Toronto, Montreal, Quebec City, etc) the going rate JUST FOR LABOUR to install (the clicking of the planks) is $3/sf. Everything else is ADDED to that base number. Carpet hides HORRIBLE subfloors. And sheet products (such as sheet vinyl) also hide HORRIBLE subfloors and the WORST surfaces for tiles. I would be prepared to pay $4/sf overall for subfloor prep. Cost of install of the tile and the vinyl will be extra. Cost of materials (tiles, vinyl, thinset, grout, etc) will be extra. Does that help with what you are seeing? Can you list the two different prices for us? We'll tell you where things are missing and where you need to add more money (or not...depends on the SUBFLOOR).