Hmmm. Interesting. You just made me think that it would be POSSIBLE to convert some of the swap.btc back to DEC to buy more cards if/when BTC spikes up and then comes down. The good news is that I now have my (gradually increasing) stash of BTC (swap.btc) within the Steem-engine platform, and so it would be easy to go back and forth. Right now my system is working smoothly, and I don't see a need to change thinks up much. Just staying the course. Thanks for the comment. Also, the large amount of SPT helped boost my card-buying, so I appreciate that.