I can just say good luck. Of course, if your market has no big PC presence, you may do fairly well, but the market is a tough-sell environment. You'll experience a lot of lookers and screwballs vs. buyers.
I've found, and I've sold a few dozen systems via this route, that $200 or so is the sweet spot which is why used systems are typically the easiest to sell instead of new. On the other hand, a couple of years back when Dell had that system with the free 15" LCD monitor for way cheap, I bought a dozen of the systems and unloaded all of them in two weekends at a flea market......basically selling the systems and monitors as separate items. They went fast, but the Dell name helped and the warranty/support from Dell did a lot of the selling for me.
And your buyers will come back to seek support even if they say they won't. It can be a big PITA sometimes, especially when you are catering to a very low denominator.