Add on top of that that I don’t have to replace a bunch of software I’m used to using and that they just tend to work better (like working in an organized library as opposed to a disorganized one), and I am comfortable that the premium is money well spent. This justifies about a 50% price premium in my book (ok, maybe a wee bit less after time value of money). My PCs tend to need replacing every two years.
I replace my Macs about once every three years on average. In my experience, Macs have a longer cycle before needing to be replaced.