Gotham is not cheap to buy legitimately. $300 for all 16 styles in the standard width. $996 for that and the Condensed, XNarrow and Narrow families.
It's too bad Tobias Frere Jones was not able to take the typefaces he designed at the H&FJ foundry before he and Jonathan Hoefler had their big falling-out. Frere-Jones did retain rights to the typefaces he designed for Font Bureau, which explains why a number of Frere-Jones typefaces such as Interstate are available to sync on the Adobe Fonts service despite Font Bureau ending their agreement with Adobe.