You seem awfully enamored with this knife.
I've had Frost knives from the 70s-80s and the ones I had and still have were made in Japan and were made quite well, in fact I still EDC a Frost Black Hawk II, it's a One Armed Razor Swayback Jack with a hawk bill, it's a great little knife.
As for the knife in your op, it looks like a copy of a Bench made, can't place the model but it just looks like a poor copy, as far as the F&F and build quality, unless your buying the knife used on the secondary market and is a quality made USA or whatever country you get what you pay for, you can't make a quality production folder for $2.50, is physically impossible.
Something had to suffer somewhere, materials, heat treat, F&F, something. Somewhere the end product comes up short and the consumer gets short changed.
I'm not saying they don't have a place in the market, my buddy would rather spend $100 and get 20 POS Chinese knives and best the hell out of 'em and their then away or not worry about losing one, ('cause he has 19 more) than to spend that same $100 on a quality blade.
(I'm not putting down China as a country just the companies that use the cheap labor and production facilities to crank out substandard knives, be it China, Pakistan or Taiwan)
IBTM