There are several manufacturers who make or have made firearms in that calibre, and cost varies greatly.
100-500 or so
No! What's the matter with you?
Absolutely not.
Yes you can.
38 caliber hand gun
Depends- WHICH 38 caliber- and which cartridge. The .38 S&W is a relatively weak cartridge, but the .38 Special has been loaded to much higher energies. SOME .38 specials have more stopping power than SOME .380s. and vice versa. The .38 Super Auto has MUCH more power than the .380.
.38 caliber revolver
No
165
That is too broad of a question to answer. There are literally hundreds of models of guns that are 38 caliber.
It was a .38 caliber Colt Cobra revolver.
Impossible to answer without knowing who makes it.