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 $2,000 on an amplifier. There are no shortcuts in RF, operating an illegal basestation can very easily affect E911 service and put you in jail for a very long time if your basestation stops someone from receiving emergency services.
I don't want to go into too many details for obvious reasons but you really do not need to spend a 2000$ on an amplifier to get more than 10 feet of range if you are building say a DIY IMSI catcher.
Just suffice to say are over the counter (if you are willing to order from china, or heck Dealextreme) cell blockers and boosters that cost <200$ that can block cell reception over a much much greater area than a 10 ft radius.
That's not true. To run a benchtop setup you just need an inexpensive SDR (LimeSDR, UmTRX or B200) and your laptop - that's not "high thousands". If you're deploying networks professionally, then yes - you'll spend thousands on proper base stations, software to control them, etc. But in the latter case you should have your spectrum license, so operating a BTS should not be an issue.
Also see my post above about 911 services.
