Wow. First time home owner here. I bought a really old house that I knew I would need to put a lot of work into which, for me, meant a lot of money because I am nowhere near a DIYer. First up was the kitchen. I had the kitchen measured, went to Lowes and bought a bunch of cabinets. Then I interviewed about twenty different handymen and contractors before I found one that I liked to install them. I had no idea how to work with a contractor but I did know how I wanted my kitchen to look. He allowed me to buy some things and he took care of the rest and I was pretty pleased with the final result. I asked him to quote installing the master bathroom and not only was his quote very high, his finishes were also not broken out and I suspected they were basic builder finishes. While looking for another contractor for the bathroom, I started accumulating things that I liked from Craigslist, eBay, thrift stores and online suppliers. By the time I found a contractor, I already had the majority of the materials I needed. I explained my vision for my bathroom and showed him all of my materials. He was absolutely fine working with what I had. For the remaining items, if I didn't have a preference, he would buy it but if there was something specific that I wanted, I would buy it for him to install. Anything that was the least bit questionable, he would look at it before I bought it. It is certainly taking longer due to scouting out materials but he understands that this is not a builder bathroom and has bought into the vision. Now that I've been through it, I wouldn't work any other way with a contractor. I stayed in touch with the first contractor and while we both agree that he would have had the bathroom done by now, we also agree that I wouldn't love it as much as I will when it's done because he wouldn't have allowed me the kind of flexibility that this contractor does. That was a very long winded way of saying that I agree with what was stated up-post in that if you can find a contractor that will allow you to purchase materials and you clearly establish who is responsible for what, it can work out quite nicely.

Have you considered soapstone? I am putting that into my ski house bathrooms. It looks good with the wood and is dead simple to maintain. Engineered products with a honed finish have been problematic for some.

Check your dimension on current vanity. What is now standard does not always fit our older homes. A friend found their 1960's vanity with not the same depth as the replacement one they bought. I thought I would just replace the yellow cultured marble top in the kids' bath only to find it is a 64 inch width while standard is 60 or 48.

Any large format tile requires a lot of prep to get your floor flat, and without deflection. It requires more costly setting materials and higher skills. It’s installation is about double in price to a standard 12x12 that no one is doing these days. Plus the required prep. Don’t hire the cheap $5 hack that never heard of the TCNA. https://www.ceramictilefoundation.org/homeowners-guide-to-hiring-qualified-tile-installer