Perhaps this idea can be more fruitfully actualized with altcoins? Some have big price differences on exchanges (like that famous story with eth and Kraken) and the transactions proceed a lot faster. The prices change faster too, though. But they mostly just grow. The only disadvantage is the potential need of different wallets to do such things with different coins and this can be hard, because you have to get used to each wallet. The fees in certain occasions might also be a hindred.