how can i get some cheap 15’s?

Im not looking for expensive JL subs,  im not looking for audiobahn/lanzer either. I dont wna to spend alot, but good quality is important.someone like Adrie ED or something like that. they spend their money on making a good product not marketing it.  they dont have to be new,used is ok if they were handled right. im just looking for something good that i can make a box and throw in the back real quick, you know?  I already have 2 L7's and they sound nice and all but i want to really hit sometimes when i dont care about having a trunk. so if anyone have any nice bad ass 15's laying around and want to get rid of them, maybe we can help each other out.

I have some Xtreme 12's they are really good in my opinion.

part # for the 15's is 154SX if you want to do a search, Sonic has them for a good price

Check out the Tempest-X by Exodus Audio.  It is designed by Dan Wiggins, the brains behind Adire Audio and feature his XBL^2 motor topology.  They are probably the best bang for the buck sub out there.  Here's a link:  http://www.diycable.com/main/product_info.php?cPath=24_93&products_id=658

I have one of those in my home theater and it is amazing.