Isn't it true that when you're willing to sacrifice something, whatever it is, it's something you can afford to lose? Maybe not at first, but gradually you come to accept it
So for me, that's just a play on words, The point is the same, gamblers understand that every dollar they deposit into a casino or bookmaker is potentially lost, so when they do lose it, it won't affect their mental or financial well-being, because have calculated it correctly.