Several years ago I had a very similar debate with myself about going to a Farscape Con. I had yet another back in March of this year, debating about a trip to a concert. Now I'm having yet another debate.
I've got tickets. They were $20 US and are for the lawn which is considerably further back than my awesome spot in the mosh pit last concert. Problem is that it's a $400 flight to get to said concert, and if I'm down in that area I want to see some of the area! Think hotels and food for 4 or 5 days, and I've got another few hundred dollars on it.
Then comes the next issue. If I'm going all that way for one concert, why not try to catch the one a few days earlier in the previous city. (same state at least but then how do I get from one to the other?) When I went to Manchester I regretted not arranging to go to Wembley.
Bah, stupid internal debates with myself.
Should I not go and save the money?
Go to the one and save a tiny bit of money?
Go crazy, spend waaay too much and hit at least 2 concerts?
One thought to keep in mind is that with the con and the last show I didn't regret going to begin with, and last month I had the time of my life and fullfilled a dream.....