blankets or quilts of quality  

Ah, ok..
...$60 for a king duvet is an excellent price.
We have a king mattress too but with the added problem of its being one of those super thick kind. The salesman assured us that we'd be able to buy sheets to fit it, but of course he didn't tell us that the selection was extremely limited and prices are exorbitant for anything worth sleeping between. Fitted sheets boing off the corners and the top sheets aren't even wide enough to cover the sides of the mattress when the bed is made up. And that is with sheets that are supposedly cut to fit 18" mattresses.
Word of advice to all: never shop for a mattress immediately after you throw your back out, and do not buy anything thicker than 12" or so if you want to have a choice in bedding for it. Amen. Carry on.
p.s. Ebay is a good source for vintage cotton sheets, new in package. You won't find any king size sheets but there are lots of standard size pillowcases out there. My entire supply is from auctions and I only paid a dollar or two per case. I even have some linen ones.

I
still sleep on the sheets I was born on
There's quality!
Or longevity at least 😉

Some wonderful suggestions. ...
Some wonderful suggestions. Spent two hours this morning researching various retailers and products. There were two that I found that seems well suited for me, although there were many I've found attractive. Pictures below. The hunt is still on.
Traditional quilts, I find them attractive in their own right. We have a family heirloom quilt roughly 100+ years old. I dare not use it! Still on the wall about quilting my own...it'll be a slow peel off.
Picture one is the design your own Olive suggested. This was fun to do...has my recommendation. Cost is high for a floor reading dog owner like myself.
Second I think is from Crate & Barrel..I think ... Marimekko, by Erja ??? Good price for this, as I've seen a yard of fabric go for loot.

yes, second is from Crate &...
yes, second is from Crate & Barrel.
First is from inmod.com

Aw, gee, Robert1960....
that's sweet, thanks....I think it's the vintage, you're only a year ahead of me!