We have been in process of building a studio for a few months now. Our budget considerations definately work backwards from the room on out.
We are still in consultations with designers, and have already had people ask to rent our space, lol. There are apparently lots of people with rigs, but not high quality space of sufficient size.
Anyhoo, if you meaning your bedroom or office, then there are lots of folks around the boards who can direct you fantastic ideas with very little budget! Some very nice and generous people here!
Anyway, we are putting a summing option fairly low on our priority list. It seems to be flavor-of-the-month right now. Not to say it isn't important, just would be careful not to make it priority if you monitors, converters, pres, mics, and compressors are not enough to warrant a $2k summing box.