Like I said above, I saved $235...quite a bit more than 50. $130 off on tires, $105 on wheels. And yes I did sign up for the credit card, and doing so gives me 6 mos of no interest. This way if I can get the miata ready in time for the track day I signed up for, I won't have to pull the wheelset off my 2. Without the credit card it would've been $175 saved, still pretty good. Also when buying tires and wheels together (from most mail-order places) you save on mounting, balancing, and taxes (another 70-80 dollars).
I would've been happier if they had the sport comp 2 available in a 205/50, or if there was a stickier option available for under 100. I bought kuhmo MX's from tire rack a couple years ago for $86 each...now they are well over 100 in the same size.