The whole setup to run something like this already runs in the high thousands. If you plan on doing anything worthwhile (legally) you will be spending nearly $5,000 on a benchtop RF cage. If you plan on needing amplifiers to get more than 10 feet of range you will be spending $2,000 on an amplifier. There are no shortcuts in RF, operating an illegal basestation can very easily affect E911 service and put you in jail for a very long time if your basestation stops someone from receiving emergency services.