Friday is Apple's 40th anniversary. If you've never bought one of their products, you're probably dismissing the birthday notices as easy-to-ignore hype. But for the rest of us, it's a day of contemplation. Some will be looking back happily on years of enjoyment—and others will be regretting that PowerBook 100 they bought in 1991 for $2,300 (about $4,000 in today's dollars!). Here’s a glimpse at what some of your own Apple purchases have cost you over time—and a sense of how much you may have spent in total. It's actually kind of intense.