Walmart has posing stools?
Every studio can use a posing stool. You know, the short little wheeled seat that you sit folks in for portraiture.
Posing stools on eBay usually go for around $50.00 (+ shipping).......they can be had at Walmart (or Target, or whatever your favorite discount store is) for less than 20.00. All you need is a little minor modification.......
Buy the cheapest, pneumatic office chair you can buy. Remove the back (they're actually shipped without the back attached so if you buy new you don't even have to do that). Most of the chairs that I've seen have a gently slope down towards the back, so I like to add a few washers between the frame and the seat before attaching to level the seat off a bit. I've even taken off the upholstery and foam, cut the seat bottom down about 2" all around, and put the coverings back on to reduce the overall size a bit. That way the seat won't show along the thigh line in a longer shot. Seats made this way are much more comfortable to sit in than the 12" disc that most posing stools come with........
You might even have an old office chair laying around that you could modify....there's nothing cheaper than free!