Bersa is a $250.00 South American inexpensive pistol. It will just never be a $600.00 Walthers
Hooter
Labor rate and no advertising budgets (andn no glossy brochures) may have something to do with that price difference....never had any problem with my Bersa (nor my friends)...the Thunder full size are used by various Police departments and the Argentinian Armed Force....so it's a service rated pistol.
You maye want to give Bersa another try....I saw my fair share of Kimber lemons...
Going back to the OP, there is no "best" junk gun...it is a contradiction in terms
There is an enormous difference between:
1) Inexpensive (Bersa, Kel-Tec, Makarov Taurus, etc..)
2) Cheap (rudimental mechanics and design but still reliable, for example Hi Point)
3) Junk (Lorcin, Jennings and any "Ring of fire" firearm)
I would say the best "cheap" brand (lowest dollar figure but still reliable and decently accurate) is Hi-Point.
Rudimental design, cheap non-steel materials (excluding the barrel) for frame and slide, extremely unbalanced, no ergonomics, horrendous triggers, very heavy, impossible to carry, ........but reliable when you squeeze your finger.
They are ok if your budget is extremely tight....you would be still better off buying a used "inexpensive" pistol (category "1" in my list) but as nightstand or truck pistol Hi Point are ok...and for some non serious plinking at the range.