I only paid $350 (+ tax) for mine... so he could get something even better.
hmm.. You can get some Focal subs for $313 each
I considered it, but it wasnt in my budget. Also look at some Rockford and Alpine (Type-R's)... you can get some pretty good subs in your price range.
If you do want a couple Boschmann though, I know a guy still selling a pair of 12's.. Model ALX-122 SP... he wants more than I paid for mine, but maybe you can talk him down... let me know