Well this is certainly an odd one. A listing for Sonic Mania on all platforms, that lacks the Plus DLC, is coming to GameStop stores in the US on November 5th, 2019 for only $20.
Here you can find links for the Switch, PS4, and the XBO version. We’ll post the boxes (including the back covers, handy!) just below as well. Right now this listing is only for the US as EB Games (GameStop’s Canadian counterpart) doesn’t have a listing for the regular Sonic Mania retail release as of yet.
Sonic Mania is already available at retailers as Sonic Mania Plus with all the DLC included for $30.
Via Cheap Ass Gamer on twitter.