You need to bring the coins uphill in the first place.
Right, but that’s easy. If desalination only required lifting each unit of water a few inches we probably wouldn’t say it’s particularly difficult.
Easy as in moving mass against a gravitational potential? Didn't know building a rocket was easy.
Moving water against a gravitational potential has been done for literal millennia and no rocketry is required. A water pump will suffice.
My point is, we shouldn't assume that fighting entropy isn't necessarily expensive. There's always a cost, and it may in fact be high, but we shouldn't assume it is.
You still have to lift all the coins.
Slide the coins off the table into the sorter, done!