looking for a used Roche Bobois sofa or similar style  

This is where the dealer premium comes in. Either you acquire objects as and when they pop up or you buy what you want for a higher price.

However, I'd suggest there's real life auction aggregates such as the-saleroom, as an alternative to eBay for example.

And while I know of some 'wholesalers'(i use that term very loosely) of vintage furniture, theyre all focused on Danish design because that's what I focus on. I'm sure however with some research you'd be able to find such sites for other niches of modernist design.

But even so, their prices aren't great. I certainly wouldn't shop from them, just better than your average dealer.

Kyle

Thanks.