Don't frequent the "local" gun shops often, but have noticed a few vendors carrying them at the local gun shows in my area. Kokomo, Lafayette, Tipton etc.. At the last show I attended, think it was Kokomo or Tipton, one vendor had several different models, I noticed that he had the 22LR with an additional 22 mag cylinder for around $350 as I recall, and a 22LR only for around $250 (not sure of the prices, but think I am fairly close).
Just a little insight ... unless you're planning on being close enough to your target to place the barrel to his/her eye socket or ear, you may want to look up the actual ballistics on 22LR AND 22 Mag coming out of a 1 or 2 inch barrel at these web sites..... very good info here to save for other calibers also.... Foot Pound Calculations & BBTI - Ballistics by the Inch :: Calibers/Cartridges ... find your ballistics at one sight and find the umph value at the other.....very enlightening!
You will find that there is little room to wiggle with bullet placement, and distance fired..... good luck with whatever decision you make!
PS I've owned a 4inch MiniMasterm Convertable.....these are very well made weapons, but with the shorter barrels those ballistics really are lacking. ALSO, a 22Magnum fired from even the 4inch barrel will leave your unprotected ears ringing ande it also shoots out about a 12-15inch flame.....BIG BANG!
Even a mini revolver is better than (only)harsh language.
The little derringers are also worth considering.
As a mini backup, the 22mag would be alright