Thanks for the helpful and funny comments everyone! Luxury spending is really interesting to think about, and falls into multiple categories - convenience (something like an ATM fee, take out instead of cooking), status (designer clothes, new car), enjoyment (travel, great food).
The first two are almost always a waste, and MMM regularly speaks against them. The third is really about value for money, and value is subjective - if you sleep easily, or wearing clothes, quality linen may not add anything to your life.
When possible, I ascribe to the "buy it for life" mentality. When I was 18 and had my first apartment, I spent like $300 on a set of discount all clad pots and pans. They're still in perfect condition (and maybe more importantly, a joy to use) 20 years later. And yes, I also have the vitamix. At the same time, I get clothes from the Goodwill Outlet for a buck a pound, drive an old Prius when I'm not on my old touring bicycle, and rarely go out to eat.
Most of us are spending beyond meeting our basic needs, so we really should use money to maximize happiness. When things last a long time, we can amortize the enjoyment over the whole period. Business accounting would actually be helpful here - buying goods is a capital expenditure, and the cost is really just the depreciation over the life of the item (plus 4%/year for the foregone investment returns).
For those interested, here's the sheet I bought (used as a fitted sheet):
https://www.roughlinen.com/collections/sheets-collection/products/sheet?variant=45871261973As another poster argued, my 5 year durability estimate is probably way too low. If you value comfort, temperature regulation, and durability, get yourself a set :)
