Borland Turbo Pascal Toolbox 4.0 - GameWorks (DOS, 1987) Two floppies with full source code for games of Chess, Bridge, and Gomoku. Retail price: $99.95
Ken Silverman's recreation of the first Doom map in his WIP Build engine circa April 1994
Classic DOS platformer Jazz Jackrabbit, its Widows sequel, and Epic Pinball were added to GOG's catalog!
Some holiday fun in several versions of Print Shop
Borland Turbo Pascal for Windows v1.0 (1991)