I think you got a pretty good price. When I was buying my MCS I looked really hard at the JCW. I went with the MCS pretty much because I didn't want to pay a lot more for an incremental increase in performance. At the price you paid for your car, you got the aerokit and the suspension parts for free; that would've made the JCW a lot more tempting to me.

 

$1200 off isn't unreasonable. I got mine for $800 off with free sport stripes and floor mats thrown in (~$400), no other markups and no financing markups on the lease on a $30,300 MSRP car. This was the first week they were in the US.