twospecialgirls, one thread a dau is still quite a lot, would it not be reasonable to say
A)sellers must have a confirmed number of posts (people already selling would already have those, would just stop newcomers scamming).
B) One thread a week, then you could work out what you wanted to sell and put it all up weekly, I can't see how a few days would really make much difference to each person, just to the board as a whole.
and
C) No continuos bumping, if people are looking for sales they can go to the sale board rather than active convos/last 15 minutes etc
D) If they want to CHAT they post in CHAT, if you want it to be a thread everyone doesn't post on why not create a 'club'? Like the teashop/sanctuary/bar/scuttlebuggers etc they are happy to have new people but mostly it's the same posters, you could always have one of your own.
???
I can't see that being a problem for sellers or non-sellers.
Just means everyone gets a fair go at the for sale board and less peopel come along, create an account and never post except on sales.