Going crazy Electrical Problems

Ok. Sometimes I will go to start my car. So I get in and go to turn the ignition. BAM!!! Everything loses power. So I instantly pop the hood and go wiggle my battery cables. Alarm goes off like the battery was removed so I reset the alarm and start the car. Cables are tightened so I know I am getting a good connection. I was slightly wondering if it would be my amp. It's a 300 watt amp. But If my amp was draining my battery it wouldn't start back up after I jiggle the wires. So then I thought maybe it's my battery. Haven't changed it because well, I don't want to spend the money and it not help me any.

Your batter cable may have a break in it or the terminals may need to be cleaned. If you suspect the battery you can have a load test done it usually for free at a local parts place. That will tell you if the battery is weak or may have a dead cell.