u can get the whole old ass add&d goldbox classics for $10 on humble bundle rn. do these games hold up well today? well, frankly. no, but in addition to the goldboxers note that this bundle also includes the perennially spammed darksun games, ravenloft, spelljammer, and a buncha other shit too.

https://www.humblebundle.com/games/dungeons-dragons-classics-collection