"What sort of customers do you sell to? Are the businesses? Individuals? Both?"
I am a project manager (Engineering background) in the commercial construction Industry. Right now I am managing a large part of a pharmacuetical research building ($200Million) for a well known company. We get price increase notices all the time as the market demand for raw materials grows over seas. It is pretty tough to stay just barely in the green. Too much in the green and competition gets the work. Too cheap and competition gets the work because we go out of business.
It sounds as though you don't have any taxable sales under the FairTax if you're selling to other businesses who use their buildings for bsiness purposes. If that's the case you wouldn't be involved in collecting taxes from them as those sorts of sales are not taxable.
The downside to that is, of course, that you don't get paid the 1/4 of 1% of the tax revenue in return for a two line report each month.