There's been a sealed one in an eBay store with a BIN of 25$ for a while. There was also a completed auction for a sealed Star Tropics and a sealed Zoda's Revenge that ended for 35$. I'd say 20$.
It's a really common sealed title. I've had 2 different sealed ones pass through my hands so far, and I don't even collect sealed. I'd say $15, maybe 20
Comments
I remember seeing a whole section of sealed StarTropics at ToysRUS after the NES had been gone for a few years.
They must have been liquidating a box from top-stock...$5 each. This was a long time ago, though, so even getting
quadruple that now wouldnt have been a good financial investment to have bought them all.