And you can build a mighty nice Cataphract-3D or any Shadow Hawk (or two!) or Jenner-D for 15MM. Any of which will give you options and a mech you'll have for a long time.
I think I made ~14 million with cadet bonus + one free day of premium, so that sounds about right. I know I was able to buy (and outfit) my CDA-2A, and also a stock CDA-2B.