From my experience, I love my spyderco byrd cara cara, spyderco endura 4, spyderco pm II, kershaw, moraknivs, opinels, Fox karambit and after long long testing…Ganzo 440c steel knives.
Yes, the locks are not as strong as some, however, the blades themselves are as good or better than knives that are far more expensive. Unlike some knives, these are labeled under their own, and while similar to other makers designs, are in fact very much there own blades.
For under $30 you can get a really nice knife- and there are dozens of styles.
I still believe in my Opinels as the best overall folding knife deal. Longevity, edge retention etc., however…