As for D&D Beyond, I'm generally a big fan, but I also don't own much physically. (Just the PHB, Xanathar's, and Ravnica because they were on sale on Amazon... and the Starter Set, though I got that before anything else because it's how I got into D&D).
As goodguy5 said, you can recreate stuff as private homebrew if you're willing to take the time. (Private homebrew is automatically shared with anyone in a campaign with you on DDB, even without a subscription.)
You could also buy only the character options you want a la carte, and the price of the full book would be discounted by what you'v…