There is a deal to be had here. I’ve played buggier versions of Civilization games on different platforms, and Aspyr support helped sort out whatever problems i had with this one. However, in terms of the cost, i’d say you’re better off going to find the game on the Steam marketplace. The complete Civ V experience involves the two 30$ expansion packs, Brave New World and Gods & Kings, neither of which are included here. So, essentially, to get the full experience, you would have to pay the initial 30$ for the Campaign edition, then another 60$ for the two major expansions. Steam bundles them occasionally for substantially less.
If you do feel like paying 90$ here, then i’d say go ahead and enjoy yourself. After two years i still find myself enthralled by this game. It’s a deep and meaningful experience that you don’t get in a lot of strategy games, or games in general, nowadays. Make sure your mac can run this game on the highest setting though. This is not a deal breaking condition, but it does look much nicer on the highest resolution.
All in all, there is a deal to be had here, especially if you’re only interested in the basic CIv V experience. But it’s up to you whether paying an extra 60$ for the full version is worth it.