You're right. I still have a concept of money though, because I've worked the last 2 summers.
do this.
take golfers suggestion, about planning the trip you were going to take. but plan how you're going to pay for this airplane.
remember insurance, tie-down(or hanger space), planned maintenance, unplanned maintenance, etc. find out how much each is going to cost, how you're going to insure you have the funds, etc.
one of the cessnas in our flight club is off-line right now, because it was/is a lease-back. the owner hasn't planned this stuff out. it failed its last anual....i can't remember for what it failed, but was told it's pretty pricey. on top of that, the engine has less than 50 hours left on it.
due to both of these issues, it's off line. the guy doesn't have the money. it's ashame too, as i liked flying that one, even though it's also the one i had the electrical problems, and a partial engine failure(misfire bad enough to inhibit her ability to climb, happened right on takeoff) in. she was a nice flying airplane.
but do that. sit down with your dad to do this. you're lucky you're in this position. take full advantage, and learn...do it right.