Just mulling over the options...
I found a desktop photo booth locally. Price is a bit high @ $140, although it seems to go for ~$100 for other retailers so I can probably bargain it down (this shop tends to overprice but is willing to price match).
The other option is to build one. I'm not sure how much materials would cost, although lights alone are ~$15 a piece (per Home Depot prices).
The advantage of the premade one is it has a light, collapsable frame, so could be stored easily. But building one, I'd either have to engineer something, or just build a less-collapsible wooden box. I'm also not quite sure of the best fabric to use for light diffusion.