There are enough people out there with big bank balances who can easily afford these prices and to them $7500 is small change.
I couldn't afford that sort of money personally so think it's crazy. However, if I was in a position where money was no object and spending $7500 to meet a fave band wouldn't have any detrimental affect to my living standards, I would pay it.
I think most of us here probably aren't rich so therefore we think it's mad to spend that sort of money but for those lucky enough to not have to worry where their next meal is coming from, it's no big deal.
Kiss know they have fans who will pay so they are going to make money where there is an opportunity.