The best thing for you to do would be to start buying very young. So when you're 4-5 years into it you don't have a damn thing to buy and your account is at $0.00. Of course there will always be little things, but just throw them on your RA account and pay him $20 a week. And keep with one brand, don't go too into debt with 4 different truck accounts. It's not really worth it.
Everything I own is Snap-On, from my tool-box to my pocket screwdriver, minus my Ingersol-Rand Impact guns, I'm not a big fan of Snap-On's Impact gun selection, the rest of the air tool pieces are great. I probably have about $15k into my collection right now. The best thing for you to buy though is a good set of impacts 1/2" and 3/8"'s and then a real nice set of wrenches like the Snap-On flankdrive plus set. They are around $400 for a set of wrenches, but you'll understand why when you use them, plus you'll have the nicest set for the rest of your career.
If you want to talk tools, hit me up on aim sometime. I enjoy the conversation.