Looks expensive........ Saw a 427R a while back. It was really nice. More than that. It was awesome. Then I walked behind it and saw three Marine Corps stickers on it. And up the other side were bullet hole stickers. I was ALL wtf?
According to Roush the price of the 428R depends on how much the Mustang GT costs that it is based off of. The 428R package itself retails at $16,999. Assuming the GT is roughly $25K-27K that would put the 428R around $44,000.
Of course it is a limited edition (only 200) so I'd assume the dealers will rape the customer for another $10K-$20K.