So, here's the idea. People can trade their singleplayer creative world (e.g. copy the save file onto a website like Mediafire or ad.fly) for other people's creative worlds, or in-game money! Once they've paid you can send them the link. I'm not sure if this'll kick off because there's not many builders on opticraft and less on the forums. May as well give it a shot.
To submit your creative world for trading, put up a screenshot of it and a price. (1k maybe?)
I'll get mine up soon, just gotta finish a build on it.
Anyone like this idea? Comments, please!