Our family is big with recycling and I think salvaged wood is a good idea. Unfortunately, the price of salvaged wood can often times be more than new wood. Why? It is a lot of labor to remove nailed floorboards in demolition. Also, domestic (USA) hardwood timber/lumber prices are depressed due to the very weak housing and remodeling markets and the flood of cheap wood and associated wood products from overseas.

You mention the rustic look, and you really need to define that to see if new wood can meet your objectives. Does rustic to you mean knots or mineral streaks or dents or worm holes or color variations, etc. You might not know it from a trip to a Big Box flooring department, but wood flooring does come in grades other than select. There is also #1 common, #2 common, #3 common, wormy, and other specialty grades and cuts. Each lower grade has features that many would call more rustic and certain features are more common in certain species/grade combinations like mineral in #1 and #2 common red oak.

Glancing at current listed prices for USA sourced hardwood flooring on the internet for direct sale to consumer or installer, I see new #1 common unfinished hickory strip at $1.89/sf, new unfinished 2nd grade hard maple 4" wide at $2.39/sf, and new unfinished #1 common black walnut strip at $2.69/sf. Also, I have recently seen new pre-finished select grade red oak strip at $2.50/sf on sale at the local big box store. Clearly, new solid hardwood flooring is very price competitive with almost any flooring product and lasts way longer than the more disposable products like carpet or sheet vinyl.

A flooring professional could more clearly answer this question, but uneven mastic on the bottom on boards sounds like a big problem from the beginning as it may interfere with getting tight nailing between subfloor and floorboard. Also, what finishes have been used on these old boards over time? There can be some serious compatibility problems with old wax finishes and newer finishes. Whatever is on there will greatly influence what it may cost to refinish.

Finally, the finish will also influence the look as much or more than the wood. Have a flooring professional show you samples of various finishes on the wood you end up choosing.

Best of luck with the flooring project.

I'll start with a big "I agree" to everything jrdwyer said.

If you plane these boards to remove the mastic you might also remove the "rustic" look from them.

Are the boards square and ready to be reinstalled?

Finding a shop to re-mill old lumber can be difficult because a missed nail will kill their planer knives. They'll want to metal detect it first, a time-consuming endeavor. Shops that specialize in antique lumber will want you to buy their stuff, not re-mill yours.

Sanding and finishing varies by region. I've seen $5 per sq foot for example. That might be cheap or expensive where you are.

Why were the boards topnailed? What is the thickness and the width?

Unless these are really unique boards, then I agree that $2.50 per square foot may be a high price.

Thanks for the input. Ideally I would like to keey it below $2.50/sq ft. for the raw material. We have seen some Hickory floors, and like jrdwyer said, for $1.89 I could get #1 common Hickory strip. A questions, for jrswyer, where did you find these prices?

Now the next question, should we attempt installation ourselves, or hire a professional installer? We are going to install about 2500 sq ft. I don't think I want to tackle the stairs, so I'll probably hire someone for that part.

I found the prices at a company called Country Plank. I have no connection to this company other than they were nice enough to send me some free samples when I was researching prior to install.

I ended up going with a different company closer to where I live (IN) to save on shipping costs and also because they buy some logs from timber companies I sell trees to. Unfortunately, the milling quality of the plank flooring I purchased was below average. Maybe they have improved since 2005?

Whoever you end up buying from, make sure to check milling and moisture tolerances and find out how out of spec. product is dealt with.

Here is a link that might be useful: Country Plank