I think it's been a bit of a vicious circle here on BC resulting in many fewer sales
A few years back, you could take a punt on a bass knowing that if you didn't get on with it, you could readvertise it and in most cases get your money back. There's so little money about now that even those able to buy aren't prepared to take a risk buying something they may not be able to resell easily. And of course all this leads to less basses being advertised.
Trouble with buying/re-selling on ebay is that you have to hike up 15% or so to cover fees otherwise you're out of pocket.