Are the new maps worth 1200 MS points? Hell no.
If you're in a committed relationship with MW2, go ahead and splurge on sumptin' nice for the lady, but if your affair has cooled off, put that $15 toward a new mistress. Three new maps and two recycled CoD 4 maps aren't going to make the game better if you aren't already in love with it, and it's not a precedent we like.
Modern Warfare 3 is set to be one of the biggest COD games yet features-wise, but it shouldn't leave out one of the best MW2 game modes in the rear view mirror.
Some alleged Modern Warfare 2 pay-to-win elements were recently added, see what they are here and how they work.