I saw some Glock 22 police trade ins for 299 if you’re interested. You’d still be in the hook for shipping and FFL, but I can’t imagine finding anything else Glock in your price range. I’ll find the link if you want.
Recoil gunworks is also good to go.
I’ve done business with them on several occasions and never had an issue.
And they have a Glock 22 Gen 4 in your price range as well.