Haven't bought GM and won't buy this either.
I like the idea of paying modders but the main issue I have with the community DLCs is that they're great ideas but terribly executed. Frankly I don't really care about the map because there are many free alternatives of similar quantity, the content is useless in vanilla and seldom used by modded servers, and the non-owner compatibility lets me play with the toys for free anyways.
If it was $5 I would get it, but I'm honestly surprised 50,000 people spent $20 on an ok campaign and a map that's useless for milsim, RP or casual modes.