I'm completely new to the world of tactical knives and plan on getting some tactical knife training in the very near future. I live in downtown Indianapolis so I carry a Kahr 9mm everyday but can't carry to work and school and feel pretty naked when I don't have my gun. A fixed tactical blade seems to be the best option for last ditch defense in my situation but I'm a bit in the dark when it comes to what knife to buy. I have a price range of no more than $80 for a knife/sheath combo. I have been very intrigued by Cold Steel Safe Maker I, Mini Tac Tanto, Pro Guard, Double Agent Drop Point, and the KA-BAR Large TDI Tanto. All seem to fit into the IWB role that I would like to use and all are affordable. I want a blade length of around 4" with a short/concealable handle that still provides good retention. What are some suggestions either within the knives I'm interested in or knives that fit my parameters?