I'm looking at starting my own IB project and have been looking at amps for the last couple of weeks. I have a MFW-15 with a bad V2 amp which sparked my excursion into IB land.
In any event, I found what I think is a pretty good deal on Guitar Center for the Behringer EP4000 amp. They are listed for $379, but their web site also has a Father's Day Sale for $50 off purchases of $299 or more.
That brings the cost down to $330 with free shipping in the continental US. Looks like a pretty good deal for a new one. You have to click on the sale link on the front page to chat with a rep to get the online coupon code. Took me less than a minute.
I pulled the trigger and ordered one. I figure I can use it with my MFW until I get rolling on my IB.