I believe Jacob over at ERE mentioned buying a $100 suit, which seems shocking for a guy who only spends $5,000 a year (or whatever it is). He pointed out, however, that as he will wear the suit for about a decade, the annual cost of the suit is actually quite low.
I think we can take this line of thinking to a parka. It might have a high initial investment, but if you use it for many years and it genuinely increases the quality of your life, then I'd say go for it.
The problem our consumer culture runs into is when they buy a parka, and then another one the next year, along with a trendier pair of shoes, and a $80 scarf, and on, and on, and on.
Remember, MMM's philosophy isn't to be cheap, it's to live the good life at a cut cost.