You are jacking up the prices way high. He doesnt have to go for the expensive models. Hes on a budget.
Pioneer dehx6600bt $110(has subwoofer preoutput)/hifonics brx1100.1 $160/ american bass xd 12" $89x2/1 probox sealed enclosure maybe $100
good wireing kit (stinger,nvx)$100. result $648 and...