This is a little late, but it came across Provenza W-Age tile that offers stair treads. A 24" wide piece was $100 though at a local tile store. It's a very pretty tile if you like the end grain look.

acm, thanks for the correction. I did notice the tile size, and obviously I don't claim to be an expert. But I had to look-up images to see it could actually be attractive, because every picture I've seen up till now has been awful. I do agree, though, that it looks nice on tile that length.

The hardwoods are extremely valuable. I would work in a medium brown that eliminates all yellow/orange/red. To do that, the stain will have to have a green undertone. That means a specialized mix for your situation. A HIGH END hardwood flooring professional can do this for you. It will take a couple of weeks to find the right colour/mix. The professional will come in and strip a section of flooring (like 20ft x 20ft). S/he will then apply different stain mixes to this area for you to view. You will then choose the colour that is the best fit for your situation. At a mutually agreeable time, the professional will come in and refinish the entire house - including the stairs (quite expensive but well worth it). The banister can then be stained/painted to match the hardwoods. The only time I would look at moving away from hardwood is in the DEEP south or in very hot climates. And it would be VERY helpful if the entire house was built on concrete and not wood joists. Tile is very heavy. It often requires wooden subfloors to be beefed up (decrease the deflection rating = no movement that would damage the tile). The wood is worth saving - unless you absolutely hate it (disregard the colour). If you love tile and wish to have it everywhere, then go for it. But realize that hot climates are some of the few places where this is considered normal. Everywhere else (any place with "winter") would find this a nuisance should you wish to sell the home. Besides, you mentioned budget. Ripping out the hardwood and replacing with tile would be double the cost of refinishing the hardwoods.

Any good carpet installer would be able to do it. Should be no more than $500.00. For reference, we typically pay around $250.00 for the stairs when they are installing the remaining portion of the house.