An ethical dilemma

Jessi and I are settling into our house well. It’s starting to feel normal to live here. Our driveway got paved yesterday, and it looks nice, although they left a lot of dirt in our front yard.

So now, they naturally would like payment. They’ll take $5,000 if I give them a check, but if I get cash, then it’s only $4,700. This seems a bit… fishy to me. I know that it can’t cost them $300 to process a check. So, there has to be something more going on. My guess is that if they get a check, then they report it on their income taxes. But if they take cash, it just goes into their pockets and they don’t properly report it. (And it’d be much tougher for an IRS audit to establish a paper trail, or something.)

So, what should I do? Just pay the cash, and hope that they’re honest people who just don’t like dealing with checks? Pay them the full amount with a check, just to hope that they do the right thing anyway? Pay cash and send in a tip to the IRS or something?