When I have surplus and the freezer is full, I usually give them to a local rescue/adoption group. I find people w/large snakes to be grateful for extras also. If you can't find a rescue/adoption org. near you, post on some of the large snake and lizard boards. As long as they are free, I think that's O.K. Of course that's if you can't sell them to some one else. Good luck, I never have much luck selling them. Unless you have a steady supply, most stores aren't interested.
I'm setting up a automatic watering system, so that when I go on vacation, all someone has to do is check the level and fill the feeders. I don't think it's cost effective just to do for vacation, but it will save me time all year.