There aren't many sources for this kind of product both on the web and locally. The only real source I knew of was Finium, a Canadian manufacturer. Only problem was the exorbitant prices they were asking. Of course a few middlemen were involved which really took a bite from finding an affordable alternative to handling stair treads and risers the old fashioned way; installing and finishing on site.
So what about the hassle of doing it on site? Sure unfinished material makes it appear more affordable, but several steps along the way create an inconvenience. Airborne dust has always been a problem. You may not actually notice it on inspection from a distance, but you will rarely get that smooth almost furniture like feel, or a similar finish applied to prefinished hardwood floors.
The amount of time and labor involved in finishing treads and risers on site can also take a bite out of the cost savings you have buy installing unfinished material. Let's not forget the odors created by the type of finish you may prefer. Some may linger for weeks depending on how sensitive you are.
A few weeks ago I visited stair-treads.com in White, Georgia. Had I known about these guys a few years ago I would have offered their products for sale when hardwoodinstaller.com sold hardwood flooring. Nine times out of ten hands down, finished treads and risers beat that strip or plank look many retailers steer you towards because they don't know of the other options.
Installing hardwood on stairs by the single plank method takes time as well, not to mention some serious tedius work if you want it looking like a professional handled it. And the costs can be up there too. Take for instance one single piece of prefinished stair molding (also known as bull nosing) can run on average $50.00. Add about 4-5 square feet of material for each standard 36" step and riser with a square foot price of $ 7.50 and your costs are $80.00. Thrown in labor and that cost can rise to $160 and more per step easily.