Charles, I'm glad you've asked the question, got the answers here that you needed, and that you've made the decision to go for it. Bully!
I'm your age, and just 6 months ago fulfilled my lifelong dream of hunting Cape buffalo. I faced many of the same questions and fears as you. But as others have said, one way or another, it's only money, and you can't buy a single second of your life back once it's gone, no matter how much money you have.
If I can add one more piece of advice, I'd have to say I'm solidly with Jorge and JJHACK on this one: do NOT shoot a cow. Shoot a good, mature, tough old bull. Don't worry about the cost. Borrow the money to pay your trophy fee, if you have to. Don't even think about the cost of taxidermy for now, just get the cape and bring it home and make those decisions after you've got the hunt behind you and safely stored in your memory banks.
