My old Macbook Pro was very good. I had it for 5 years, and it was hard-wearing and reliable. I'd probably still be using it, only it turns out that, while durable, it wasn't splashproof.

Most of the "savings" for me over that period came in terms of reduced hassle and bother. OS X proved reliable and low-maintenance, minimizing the amount of time I had to spend playing IT man. And, unlike Windows, it didn't fuck up over time, even proving resilient to upgrades (I did every step from Leopard to Mavericks), so the regular reinstalls that I was used to doing weren't necessary. (And, unlike Windows, it had a decent backup tool supplied, so when I bought an SSD, which was the closest I got to needing to do a reinstall, I had to do little more than leaving it running overnight, unattended, once.)

Of course, things progress, and Windows vs OS X is moving closer to parity... thanks to efforts from both companies. But I replaced my soaked Macbook Pro with a new one anyway, on the basis of my experience - it certainly wasn't the sticker price, that's for sure - and it's working out OK for now.