I'm not up-to-date on the SNES scene, since I got a lot of the must-have games I wanted on it a long time ago.
But from what I recall, here's a few that were cheap:
-Darius Twin
-Final Fight
-Gradius III
-Hook
-Maximum Carnage
-Mortal Kombat 2 & 3
-Separation Anxiety
-Sim City
-StarFox
-Street Fighter II: Turbo
-Super Mario World
-Super R-Type
-T2: The Arcade Game
-X-Men: Mutant Apocalypse