I feel like most people would've gotten stuck on the whole not-real bit, but yeah, planet. Space travel is kinda a thing sometimes; we get bored being stuck in one place.
Sorry if this is a dumb question 'cause I've no idea how Leprechaun Gold works, but you can't substitute pyrite for gold or something like that? It's real, won't pop out of existence, highly reflective. Unless he senses the monetary value a society places on things, which would be a bit weird 'cause that often differs based on culture but would also be an amazing ability to have...