AaronOfBarbaria
Adventurer
That gets into heavily subjective territory since what is "no big deal" to you looks like "a particular character with a particular spell chosen, a substantial monetary cost that has to be planned in advance to be sure its even an option, a significant cost in resources, plus a potentially huge detriment to the party's goals" to me - or to phrase differently, seems like very much a big deal.This is the tricky part though. If raise dead is no big deal, the game is less challenging...
As for degree of challenge, I have never found that the expediency of being able to continue on after a failure actually changes how difficult something was to begin with. I mean, Super Mario Bros. isn't made easier by having effectively unlimited chances to try each level - you still have to actually make it through the level. Sure, one could say that the game would be harder if every time you died the game completely reset and you had to start from world 1-1 again - but that is a different sort of goal; that's the game being harder to finish, not harder to play.
I've never seen any players behave as if it doesn't matter that a character died - even when running with experimental rules that there were no penalties at all for coming back, no limit to how often it could be done, and no cost to it beyond a character having and casting the appropriate spell, and even when I gave the party a rod of resurrection at the beginning of a campaign - the players tried to avoid character death because to die was to spend more resources than if not to die, to take longer than if not to die, and often enough to fail to achieve some goal because to die was to miss the opportunity needed.