$250 for exhaust and points?

[72blacksuper]

I messed up my exaust when i bottomed out my 72' super this weekend. I need a new exhaust, i can get a performance exaust, header and j tubes with new points all that installed for $250 is that a good price? The guy at the local vw shop said for me not to run my stereo with the car off because it burns up my points is this true? My car back fires alot right now and runs like crap keeps stallin and stuff i think its because i dont have the right back pressure because there is a 1" gap between my exhuast manifold and my muffler on the right side of my car. Could the points have anything to do with the car running bad to? Thanks for any help. I dont wanna dump alot of money in to it, but i want it to run good for the next two months before i go in the army and i maybe want a little more power outta it with the exhaust. Thanks again.

Peace,
Wil