It's worth the price..
MaddenBowler10 wrote this review on .
The campaign itself is relatively short depending on how long it takes you to beat the last level. It feels like Valve didn't put much time into it. They just re-used the last map that was on The Passing in this one with a different objective.
No mercy speaks for itself, great fun and length.
It's really up to you..I'm all for buying the maps whenever they come out because it's nice to have as many options. This one includes two maps so it is probably worth your money.