You know, I almost forgot one other thing that can happen with rewards. My middle son very quickly discovered the art of negotiation. As soon as that happened we had a choice between going broke or stopping the rewards altogether with him. 
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I'm not likely to be around much longer. As before when I first signed up here years ago, I'm finding that after a long hiatus, and after only a few days back on here, I'm spending way too much time here again already. So I'm requesting my account be locked, banned or whatever. It's just time. Until then, well, I dunno...