The cheapest I saw was around $400 give or take plus shipping. The JL 1000/1 will work perfect with that sub, just make sure you wire it for a 4 ohm load and not a 1 ohm load.....the sub is a dual 2 ohm.
As far as how it compares to the IDmax, I hear that the IDmax has great SQ and gets pretty loud. I have the Brahma right now and love it but I could not tell you how they compare, from what I have read they are pretty similar in over all spl and SQ, hope this helps.