Well, I may have bought it before, but this is the first time where it felt like a key part of my win.
http://dom.retrobox.eu/?/20130825/log.50bf7f45e4b06eb53227757d.1377415921341.txtBaker in kingdom. Because my opponent buys Cultist turn 1, I'm safe in picking up Beggar for the reaction. My Beggar activates almost literally every time it's in my hand. Might be luck, might be Cultist stack. That, plus Trading Post to help thin my deck early on, plus Fairgrounds + Ruins, means I get a "slog" deck that goes for large Fairgrounds, except because of the Beggar Silver flood I can actually afford Provinces (which I skip because Fairgrounds are just better for my deck.) This is despite losing the Ruins split 8-2.
First time I've noticed how strong the Beggar reaction is. It doesn't stop the attack, but two free Silvers is a lot.