Honestly.........
This question has come up before and my advice is call some of the local truck repair garages in the Lehigh Valley and ask what their 'Hourly Rate' is.
When you hear that number, you'll then be able to decide if it's afforadable for you or not. Keep in mind that no tow company will even start one of their wreckers for under $150.00 to come pick your truck up should you need it towed.
Best thing to do is start out with a smaller vehicle that you can work on, then move up to a larger vehicle if this is your passion.