I think getting into Hell is probably free. Getting out...
But there's a really obvious reason why Heaven wouldn't be reachable.
Wizard: Ahhah after centuries of research and mapping of the ways I have located Heaven. Apparatum!
*spell fizzles*
Wizard: I don't understand my theory was perfect, my analysis complete, my...
Angel: Hey.
Wizard: What how'd you get in here through my defenses?
Angel: Look that's not important, you need to stop what you are trying, it won't work.
Wizard: Oh yeah says who?
Angel: ...Him.