Okay, let me point out that passing out anywhere... you get no energy recovery, and all you'll lose is 1000g. Period. Using a sleeping bag, as proposed, would prevent that cash loss and allow for some energy recovery? So, basically you're paying (if 2.5k and 3 use as TrailerParkThor suggests) 2.5k to avoid losing 3k. Okay, a slight improvement over how things stand, if you think ahead and prepare for it. I can get behind this.
So long as it can't be used to keep you on the same floor of the SC when you go to bed, I'm down. Hell, I'm fine with folk using it wherever they'd like... but if used in the mines or SC, it could automatically punt you to the entrance floor when you wake up?
May I suggest it work automatically too? If in your inventory, when you pass out... you wake up where you were (except in the cases where it punts you out to entrances of mines/caves), no/reduced energy recovery, no cash loss.