HOw much to ya think a 4x2x2, 5 foot or 6 foot tank would cost to set up? what would be a good price to pay second hand?

Hmmm, All brand new? I'd expect somewhere around $2K for the tank, stand, filters, livestock. Secondhand...Varies hugely depending on how desperate people are to get rid of them. I got mine for $400 all setup and running.

Depends what you set it up with. A bare 4 x 2 x 2 tank cost me $80 but I have heard of others getting them for less (and more). The type of stand will affect the cost too with solid wooden ones being more expensive than metal. There are a lot of factors and I guess it boils down to how much you are willing to pay.