Note: DAZ3D is having an 80% off sale of V4 and related figure products in honor of Smith Micro's new Poser release. Sounds like a good time to stock up...

Renderosity has a good catalog of older V4 products. Check out the "Vintage" Marketplace section. New products for V4 and family aren't as common as "Generation" figure items, but one or two will generally pop up every few days, either on Renderosity, DAZ or RDNA and other sites.

On V4 "not needing new content" - Actually, V4 could use some new content... We've got a new version of Poser out and there could be some nice features that new V4 products could use. The problem with "content" with V4 is that there are only about three-hundred and twenty different variations of "wearing almost nothing at all with as few polygons as it takes to create" products that the market will accept... Many of the top content-creators work at the crest of the wave, which is only sensible. But, that leaves the market trolling the depths, sometimes. It's going to take some imagination and skill to produce breakthrough products for V4 that are exciting and attract customers who have been using V4 for a long time or are already hooked on "Generation" characters.