1st, it was short notice because we are in a pinch due to the pig's , we are in fact buying these platforms of the USN rather than Boeing. Therefore we weren't in a position to negotiate.
2nd, quoted platform prices are fickle things. The tricky thing is a platforms actual price is actually quite hard to determine, its not like a car. Every deal is different, and therefore the price for a fighter changes for every different customer. The $45m figure could be a number of things, it could be a UFC, a UPC it may be bare bones, it may be ect. Every deal includes hardware, logistical support, weapons, spares & training. Therefore the actual price can change quite a bit between deals.
Anyway i'm not sure we got such a bad deal. IIRC the recent Algerian(?) deal for 24 F-16 Block 50's (much cheaper and less sophistocated), if all the options are taken will cost $2.4bn USD, we spent $2.9bn on 24 SH BII's. Not too shabby...