I am buying my first kirpan but it seems like they are pretty expensive; I have looked on other knife sites and there are knives which look in some ways similar to a kirpan. What is the technical (physical) difference between a knife and kirpan? I know a kirpan tends to have a metal or wooden sheath, whereas most other knives come with a leather sheath. Can anyone help me? Or suggest some sites selling nicely priced, sharp kirpans?