That's a good point. A quality lid costs a much as a Glock these days.The Annoyed Man wrote: how much money one is willing to spend for a pistol is analogous to how much money one would be willing to spend for a motorcycle helmet... ...the operative question being, "how much is your head worth?"
As far as what's my head worth, you will get various opinions depending on who you ask!Back to the OP, a new, quality gun for under $300 is a tall order. Taurus and Charter Arms both make some decent revolvers that are just a bit more than that. There are a few nifty .22 mag revolvers by Charter Arms and NAA that will fit that price range, and while that caliber is a little too small for serious self defense, it's more that adequate to take care of common street criminals.
If 'new' is not a requirement, there are awesome deals to be found in pawn shops if you are willing to spend a few weekends hunting. I remember the day my brother came home with a Winchester 1300 that was cherry and had paid $150 for it. Granted, you gotta search a bit, but you can probably get a lightly used Ruger or S&W and stay under budget.