The most common reason folks choose finished flooring is for the 'fume' problem, shorter installation time, actually costs less. The unfinished flooring is less expensive up front and does allow you to pick whatever stain you want but you lose in a lot of ways when it comes to the finished aspect of the flooring.
The controlled conditions in a factory are not normally duplicatable in the home. (IF they were, we wouldn't be talking right now.) In the factory, 5-9 layers of poly are able to be applied. In the home, 3 maybe 4 layers at most are done with perfection due to the environmental conditions. There are so many mfgrs out there that one would be hard-pressed to not find something to their liking. About 10% of a box of finished flooring (2 sq. ft. out of 20 sq. ft.) is usually not usable. So, normally, a room is sized on it's square footage, then you add 10% or so for this. We leave the homeowner the 'scraps' in case they ever need to replace any boards (as well as whatever over-run stock there is.) I'd never resand and refinish a pre-finished hardwood floor board unless I'm doing the ENTIRE room.