$5 Add +1 to the speed multiplier for 30 seconds.
This effect stacks!
$7 Everything is invincible for 30 seconds.
There is still knockback from being hit, and falling will kill.
$8 Disable gravity for 30 seconds.
$15 Randomize the enemies in the game.
This immediately kicks me out to the game's title screen for the randomization.
$175 Restart the game.
This is like a soft NG+!
I'm returned to the beginning of the game with my current inventory and levels. All bosses are respawned, and all shortcuts and bonfires found are reset.