Guy at work asked what a good pair of 18's would be, i asked his budget for subs, he said $1000. I said, you realize that if you spend that much on subs alone, you will need like $800 in electrical. I think he changed his mind.
I think he is leaning twords two sa-15's. We can get him set up with those, box, amp and electrical for right around $1000. If he is serious, we will see.