I'm a 100% you will buy it back at ge price unless it is some kind of glitch that is making it buy and sell for the same price which I highly doubt because it would of been patched by now lol.
test it out on something cheap like a glory, you may only get like 10k for it and see what the price is for the shop/ge but if it did work it would make RWT super fast and pointless for the "trade limit"