That seems like a good deal. I just traded in my 2012 GT premium and I got more than that for my trade and bought my 2014 using x-plan.
I thought long and hard about the 2015 before I got my 2014. I don't hate the 2015 looks but I do like the 2014 a little better. With the deals the difference in price is going be in the thousands, not an insignificant number. Final reason is that by now the bugs have been worked out in the 2014 platform so my odds of a trouble free experience are way better with the 2014.