Notable events such as sports games have a highly visible impact both in the media and at the event location itself, but the pre- and post-game activities of attendees -- and their spending around such events -- are much less evident. In this work, we use social media footprints to analyze and interpret these broader ripples of activity: specifically, we examine the temporal, spatial, and microeconomic patterns of baseball and basketball game attendees' activity around game events for 21 North American cities and 32 teams during 2010--2014, using mobility and price data from the location-based social network Foursquare. We identify some universal spatiotemporal patterns that hold across both sports and cities: exploiting additional information about venues' price levels, we find that, in aggregate, users who check in later at the game come from pricier restaurants and bars. We use these insights to predict the costliness of a user's choice of restaurant/bar, based only on a single transition to or from the stadium/arena, using the temporal properties of the transition such as the time of check-in at the game, distance traveled, and speed of transition, with the last being the most important factor. Our analysis carries broad implications for human mobility studies, mobile applications, and sports economics.