Well I originally had four Kicker Solo Baric 15s in a 1990 S-10 Blazer (my first car which I miss dearly) and the subs ate amps like candy not too mention alternators. I started with 8 gauge wire...that did not work so I upgraded twice till I had to just accept the fact that I had to use 0 gauge or do not even bother. I got into car audio because when I was at CAL (college) I lived with 3 Asian guys and they knew some people who knew some people who stole sum $hit (you know the story). Anyway I pieced together a comp. SPL system using their "friends." So to be honest the cost was not that high unless you price it out retail.
So in their original form I ran four Kenwood amps all bridged up one to each sub and the subs killed those amps (under warranty thank god) so I got a new set and gave kenwood one more chance. No luck they died about four months later. So I stepped up to ALpine (POS) then to Kicker (POS again) then finally rockford. I used four amps but that never seemed to work so I opted to step up and run two 1000 watt amps. I had to run 3 1 Farad Lighting caps strung up together to keep the lights from dimming. Then came the power draw and I needed to have a backup battery because I wanted to run in the SPL comps. So I had to get a two battery system hooked up. Finally I had all the kinks worked out with two rockford 1000a2 (with spec sheets stating at two ohms they were kicking out 1500 watts at peak and around 700 rms) so I went out and ripped up the novice class after dyna mating the whole freaking car which added so much weight my gas mileage went to poop. I got kicked out of the novice class after picking up some hardware and by this time I had graduated college and I did not have a steady hook up for the hot parts so I did not want to foot the bill for staying comp. at the next level.
So I sold my blazer and ripped out the stereo system. I put the other two 15s in my gfs acura integra and pieced together an award winning acura integra for the novice SPL comps. Then, my now ex-gf, got t-boned by some idiot and her father sold her car with the fu$king stereo in the car!!!!
Well I kept two of the 15s from above as well as one of the amps. IF you paid retail for all the above the subs are about $350 a piece, $100 for a decent box, $800 for the amp, $300 for the wiring, $100 for professional install. I was lucky enough to have some friends who work at audio shops and bestbuy (the devil) so they hooked me up with the wiring and my audio friends did the install for a couple cases of beer while hanging out on the weekend and some pizza as well.
The funny thing is my car's exhaust sets off more alarms than my stereo as I do not need to blow away everyone on the road these days and the guys who are always bumping their shyte on the road ALWAYS have the worst sounding systems all I hear is cymbals and way too much bass with not enough high end. They dump all their money into the subs and do not invest in the high end which is the worst possible thing you can do. I hate not being able to hear the high end....