Though this was briefly discussed in the midst of another thread, I think it warrants its own topic. MLB has just announced its 2013 MLB.TV prices (for mobile and connected devices, not cable or satellite). They look to be the same as last year. The basic offering is $109.99 and the Premium is $129.99. The latter includes the At-Bat subscription and other benefits.
Details here.
P.S. It says over 150 spring training games are included, but they are not mentioned specifically yet, as most clubs have yet to announce their TV plans.