Unfinished vs. Finished Hardwood ?
I would say you might want to consider #1 common unfinished red oak. While you mentioned "cheap" you also mentioned "reliable". Very often you will find that #2 and #3 flooring contains splits, shakes, knots and other defects that would be structural problems that come with the culling out of the color variation for these grades.
Most wood flooring is made from the same source and graded after it is milled. The grades of oak flooring are from best to worse are Clear, Select, #1 common, #2common, and #3 common. There is also quartersawn which refers to the direction of grain in relation to the surface of the flooring.
The basic differences between unfinished flooring and prefinished flooring are as follows:
Prefinished flooring is finished at the factory under controlled conditions. Unfinished flooring needs to be sanded on site which can produce dust that has to be dealt with.
Prefinished flooring often has a micro bevel to allow for differences in height between boards. Unfinished flooring has all the gaps filled in the sanding and finishing process. This makes for a smooth, tight floor with no grooves.
Prefinished flooring allows for you to move all the furniture to one side of the room, install up to it, move the furniture on the new floor and continue installing. Unfinished flooring requires moving all the furniture out of the room.
Unfinished flooring allows for more creativity in your floor such as inlays and borders.
A good source of both unfinished red oak #1 common and prefinished oak flooring is both Home Depot and Lowe's. Compare the price of both and the difference is the cost of the finishing process at the factory. You need to decide if that savings is worth the "sweat equity" you will put into the unfinished flooring.
I would also suggest that you closely look at the difference in cost between #1 common and select oak flooring. Select is a much cleaner and uniform wood and the cost difference isn't all that much.
We've been looking for wood flooring for the house we're in now, and were burned from an unreputible supplier, so buyer beware. If you order on-line with a credit card, make sure you get your purchase BEFORE you can cancel, generally 90 days. No exception, don't wait longer to cancel in writing with your card company. BeaverHomes has taken many folks for $200,000. I just ordered from Lumber Liquidators.
If you still want to opt for an unfinished floor, you may consider Brazilian Cherry. It's 80%harder than red oak and there is more availabilty on the market right now so the cost is often less than select oak! Plus, the cherry is a much richer looking floor than oak- great for your home's resale value!
For more info go to www.nwfa.org. The National Wood Flooring Associations website.