I regret walking away from a few blades in the wild. I recall one of my first adventures at an antique store passing on a large FR because I thought the blade face was too scratched up. Another I walked away from was a C.V. Heljestrand because it had too much rust, but was only $8. Passed on a few real nice vintage strops cause I thought they were overpriced.
I regret buying a Sigma Power select 2, 1k. Hate that stone.