In 2009, I purchased an iMac, an expensive product at that time, but I got it on sale. Still, it was almost 2x the price of a comparable windows machine I would have put together myself.
Just last month, I ripped out its DVD writer drive, replaced it with an SSD, and fused it with the internal hard drive to make a homebrew version of Apple's new (and awesome) fusion drive, and upgraded the memory twofold. The performance difference is staggering - I now essentially have a brand new computer.
Could I have purchased a windows machine? Yes. I would have also replaced it 2 years later, that was my normal PC replacement schedule.
THere would have been a lot of cursing and swearing throughout the ownership process. I have essentially zero complaints about my 5-year old mac.
I think that as an aspiring mustachian, my takeaway from MMM is that you don't necessarily want to buy cheap crap - buy what you NEED (I needed a reliable personal computer and my level of frustration is something that directly correlates into dollars - I'll pay more for something which makes me less frustrated), and don't throw it away and replace it the moment something new comes along. So instead of a new $1200 iMac 5 years later, I upgraded mine for $150 and will be using it until it gives up the ghost. I've mastered mac administration, am very comfortable with terminal, and have an extensive working knowledge of the deepest innards of Mac OS.
Side note: I've been doing IT for 10 years. I'm an MCSE and make a living fixing Microsoft's shitty products. I'm glad I don't take my work home with me.