110-120 amps isn't true, you never calculated the efficiency, if the jbl 1200.1 did 110 amps of ccurrent, it'd be nearly 100% efficient.
almost no class D amps are even close to 90% efficicent
so, lets say the jbl 1200.1 is 80% efficient... that's 130 amps of current... a deal different if you have a 130 amp stock alternator.
unfortunately, even 80% is a good find, class D does not mean it's actually in the 80 percentile and up. I've asked a few people who have had both amps, they said that the JBL draws a noticable amount less, and puts out about the same power. I'm not dissing bahns at all, I'm just trying to get you the best for the money.
anyhow, i suggest you look for the audiobahn from ebay or other online stores, finding it for $350 is easy.
ALSO, look at these other amps for similar price ranges, all just as good:
Cadence A7HC $350 (might be able to find it for this much)
MTX 81000D $360
Hifonics Hercules 1500W $343
adire/ampman revolution 1500w $369 shipped (ampmanaudio.com)
I cannot think of the other goodys at the moment...