• Enough nic to last until you're over 100.
• Gear that you're confident will last equally long.
I haven't promised not to buy more stuff, but I haven't bought much stuff at all in several years now.The problem is you'd have to promise that you aren't buying even more stuff even after you're all stocked up and I bet there's no honest person here who would make that promise. He, he...
The way my brain works, forbidding myself from doing something is counter-productive. If I do that, a part of me will rebel against it. E.g I've never forbidden myself from having a cigarette if I really want one; I just haven't had one in over 5-1/2 years now.