We're used to settling on pre-set limits for things like office Secret Santas and Pollyanna gift exchanges with girlfriends, so why not make it a rule this holiday season? Contact the people on your long or short list and ask how they might feel about putting a cap on holiday spending this year.
Do some preparation before you make the call by creating an overall budget for yourself, and determine how much you can afford to spend on each person. When you make the suggestion, say something along these lines: "I'm so excited to exchange gifts and spend time together, and I was thinking it might be a good idea to set a spending limit this year. How would you feel about giving each other gifts that don't cost more than [fill in a dollar amount]?"
Nobody is going to feel like you're pulling a cheap trick in this economy, and they may very well be relieved at your suggestion. Have you agreed on any spending limits so far?