There is a classic car dealer near me in the next town over.

Other than on the first few sunny days of spring, the place looks like a ghost town. From what I have heard, 90% of his business is advertizing over the web - Epay, craigslist, etc. I would think you wouldn't need a fancy bricks and mortar building if you are simply doing that. A bombed out warehouse would work with some nice lighting and a background for photography. (I'm sure a few bikinis would help too) :D)

Property taxes, business taxes, insurance, etc are incredibly high, at least around here too. But I'll stay off my political soapbox for now. And that's before you even pull the first car through the door to sell.

I'd expect a few year's worth of operating loss before any kind of profit shows up.

All I can advise is "be careful!".