Ben - when you graduate (*cough* C# *cough*) come see me. I'll see to it you clear more than your tightwad parents (I'm avoiding using stronger words) within 10 years. Stick with it, it WILL pay off.
I don't know your parents but from what I read here thats just bad parenting, and selfishness on their part. You especially don't set up an expectation of support for your child and then balk. Not supporting your child doesn't teach them a "life lesson" - its always just an excuse, a rationalization for not giving to your children and keeping for yourself. Or a rationalization to sooth the pain of failing your child. Period.
Your old man looks at a college tuition cost and then deems its not worth it "cuz he's doing fine"? Bullshit - he's doing lucky, is what he's doing, and shit else. I'm sorry but people not supporting their offspring really pisses me off. I'd be glad to have a heart to heart with your dad and show him why, distinctly, logically, factually, and succinctly, why he's full of shit.
Make sure when they're old not to give them one damn red cent for support. Or, if you're nice, total up your 18 yrs of living expenses, amortize that, and then cut em a check and tell them to fuck off.
One last piece of advice: DON'T PLEDGE. A frat will NOT help you either stay on track academically OR financially. In fact just the opposite: statistically it will cost you more and you'll do much poorer gradewise.
(I was greek... for two years then said fuck it. Sounds like you have your other priorities straight, don't go greek its just noise... ROTC, now thats a different story )