I spend around $400 a month, distributed pretty evenly between Rendo and DAZ.  Every once in a while I'll pick up something at CP or RDNA.  Can't remember if I've bought from Poser Pros yet or not.  I mostly get models at DAZ, but I prefer the texture/character sets here at Rendo - there's more of the gothic/horror or just plain weird stuff I like available here. ;) I recently bought V3, just to be able to use samildanach's V3 character sets.  Also, I pretty much buy everything that becomes available for ball joint doll, as I adore that model.