IL
Whatever you did for your Dad in the past should have no bearing on what you do today. Sounds like you are "keeping score", which is an almost certain path to a miserable life. You aren't entitled to do something stupid just because you helped him in the past.
As the father of three 20-something sons - if I/we were ever in a similar situation - I would be seething if one of them went out and bought any type of luxury item. Until you pay your own way, you do what I say. Just saying.
Credit to you for discussing it with him first, and I understand the desire. But really, just get past it for now and take care of business.
