The price I got was under 1/2 that cost, but my injectors are brand new in the box as well. I bought them a while back, haven't had time to install them and heard about these 4.5s, so I got ahold of the dealer to find out what the story was. I'd post the price, but I'm not sure if it's "public" info.
The 4 is a 150hp injector and the 4.5 is a 175hp. Mach 6 is a 220hp.
I would have went with a 6, but I tow with my truck (reason I have it) and I didn't want to worry about EGTs so much. I'm sure it'd be fine with twins, but my wallet is only so big too :hehe: