Bioshock Infinite is available at discounted price (EUR 25.99) at macgames.fr. While not officially supported on Nvidia 320M chipset, it seems working well. Moreover using new Mavericks free OSX update, performance may be even better (then we may not need the new $2999 mac pro and keep the old mid-2010 mac mini – very silent and power efficient with an Intel SSD).
Aspyr reported Bioshock Infinite’s performance problems on Mavericks when using Nvidia graphics cards with high settings.
UPDATE : the game indeed runs fine on a mac mini mid 2010 (8GB ram, 320M, Intel SSD) with default low settings (sets textures to very low) at 1280×800 resolution, and still looks good (providing you don’t look close to some textures – it however keeps nice lightning effects). Using custom mid settings (medium textures level) we get more detailed textures while keeping a playable game, however the framerate stutters (pauses) regularly, which may be due to the Mavericks/Nvidia bug.