So I've completed the uncharted map and a regular map so I have access to the blue building and the omen islends. Right now I'm just wondering what prizes there are for completing extra maps or if I should just sell off my extra pieces. Thanks!

No extra rewards for completing additional uncharted maps (that just gives Omen Islands access) but you'll still get the usual rewards for the regular map (a small sum of SP and a few rares.)

thanks!