Do I have to buy D&D books twice?

My wife and I both GM D&D 5e on roll20. We want to get some of the books. But it seems as if we have buy each book twice; one for me, one for her. Is that really how it works? Not that I'm going to boycott roll20 or anything, but if that's the case, then that's a big ole pile of cow poo. Anyway, can someone confirm this? Thanks.

Well, you could buy the books on one account, and have that account create all the games.  Then when the person with the other account wants to run one, the creator account promotes the other to GM status for that game.

More info on Compendium Sharing available here. Another option, if you both want to run games: I doubt Roll20 would care if you and your wife made a Family GM account, which handled all purchases. Each of you could use that to create your own games, and keep separate player accounts. But if only one of you is going to run, Compendium Sharing is the best way to go. Your wife would have full access to Compendium materials in any game you share, just not outside the game. If you create a module (and don't promote her to GM) she will have access to Compendium (PHB, MM( info in that game, but not module GM-level stuff, like maps and adventure text (ex: Curse of Strahd).