well if you get a theif looking at 2 cars. one with alarm, one without what do you think he will chose? there is no real need for thieves to 'research' your alarm because there are plenty of people out there with no alarm to keep them busy. sure if you have a really special car they may go to the effort of disabling your alarm to steal the car, but most will just move on to the next un-armed car. sure it wont stop any determined theif, but the main benefit of a decent alarm is it means you can get insurance. it may not seem cost effective but it's well worth it if your car is stolen. also you say $3000 a year? that is crazy, but even if that is the case if you took up that policy the premium would most likely halve the next year.
also, if a good alarm is so worthless why is it that every "my car got stolen" thread I can think of in the last year none of those cars had alarms? also personally I've had many cars and only even had one stolen, and it just had a basic factory fitted thing. all the others have had reasonable alarms. could be coincidence, but maybe not.