I recently bought one of these ex-Swiss Army fleece sleeping bags to use as a liner in my car-camping sleeping bag, which itself is ex-Forest Service and cost under $20.
For $5.97, how can you go wrong?
It would be good for napping in a cool house or for keeping in the vehicle in case of an unexpected sleep event.
I don't think you could buy the fabric this cheap at a store, as long as you like a sort of purplish-blue.
(This post hereby begins a new blog category, cheap gear.)