I've only been married a year, but I'm a quick learner. Listen to all sides. Think about it. Then make a decision. No arguing, begging etc. This is the way it is, end of story. Wife might not talk to you for awhile, but that is better than listening to hear nag about something.
I'm in a similar boat. My stepson is going to college in Jan. While we are working to pay for it, he is out looking for a motorcycle to buy.
I told the wife, "if he buys a motorcycle he must have enough money that he doesn't need any of mine."