Renderosity used to automatically remove things that didn't sell well enough.

They've changed their policy. Some vendors put items that had been removed back on sale. Some didn't. There are several products I wish the vendors would put back, but they appear to have wandered off and aren't into Poser any more.

There are a few items where you don't get notified if you've already bought something, I think because the vendor re-uploaded it as a new product.