im sure there are tons of unsuccessful office building which are completly empty for years,they are few around here and i bet you can get a realy good deal on a rather big renting space and can even break some walls and stuff if you need to.
problems with that:
1.you have to invest in a security system
2.you cant get up in the morning,walk 10 ft and be inside your studio :D

that's a good point - we now do have a room in an old building, my friend's living there in a flat and has an has an empty room with extra space (so security system is not needed) - great accustics, i can tell u ... and we're allowed to turn up the volume as much as we like *yeeeehaaaaaa*, but i have to drive for about'n hour to get there :(