Reddit has a pretty robust sale of windows licenses for $15-25 and then you can upgrade them from 7 to 10 if you want to go cheaper. edit: I don't necessarily

Reddit has a pretty robust sale of windows licenses for $15-25 and then you can upgrade them from 7 to 10 if you want to go cheaper. edit: I don't necessarily know about their legitimacy, and I've never used them myself.