I think high ticket prices were definitely a contributing factor in the death of COI. Tickets were just so expensive--and honestly, hard to justify for 2 brief hours of entertainment. One thing to remember is you usually don't go alone to these events. So it's not just $60 for a single ticket--it's $120 for a couple, or (gulp) $240 for a family of four. That's a lot of money, and that's not counting drinks, food, parking, etc.
If they had cut ticket prices in half, I think they would have sold a lot more tickets and also had more satisfied customers. When you're paying $60 instead of $30, your expectations are higher . . . which speaks to my next point.
It's my personal opinion that the quality of the skating in COI wasn't always what it should have been. I watched many COI shows on TV, and went to one COI live. In most cases, I was frankly pretty unimpressed with the skating. It seemed like very few jumps were attempted, and some of the skaters just weren't good enough artists or performers to carry off a program with no jump content. (IMO, only the most talented skaters can do that.) It wasn't like the programs were terrible, but a lot of them weren't great, either. And for a $120 or $240 investment, you sort of expect something on the great, or at least very good, level.