Hi Kay,
I can't really answer your question but I believe they're probably about the same. Aspen and Snowmass are incredible mountains - there's no doubt about that. However, everything off the mountains is so overpriced that it makes a family vacation outrageous. Since you're asking about price, I want to mention that Colorado has a lot of other fantastic resorts that aren't as high-priced as Aspen/Snowmass. My personal favorite is Breckenridge. It has terrain for all levels, beautiful scenery (like all resorts in Colorado, it seems!). But the thing that I like so much about Breck is the town, itself. It's a quaint old mining town with a nice variety of restaurants, clubs, boutiques and art galleries. It's all located on Main Street, which is a super cute, old-fashioned looking street. It's really charming! And the people are so much more down-to-earth than the people at Aspen.
Give it a shot if you haven't been there before. I always use Summit Vacations for booking my lodging. They have the best variety of condos, townhomes, etc and the cheapest prices. If you ever book a last-minute trip, they give you 25% off.
http://www.summitvacations.net/Have fun, wherever you end up!
Karen