You have to consider the condition of the booth; some guys don't keep them clean, which would be a PITA to even dismantle.
Especially the ducting behind the filters.
You need to have adequate electrical, gas, and deal with venting.
Some things like control panels, switches & stuff may have been discontinued and require adapting and/or updates.
Handy to have if you're doing much painting.
You need to get a look at the insides, exhaust side, and repair-parts situation.
Then there's placement inside the shop, for best hookups & venting.