Grant Erwin wrote:
....
Anyone actually know of a real source for paint thinner/mineral spirits
in the Seattle/Eastside area that's cheap? ...

Paint thinner has a standard sale price of $1.99/gal (around here,
anyhow). Amazingly, it has had that sale price for at least 14 YEARS!
Through all the oil price gyrations, paint thinner goes on sale for
$1.99. Bob