While tactical pens might be a formidable weapon to those properly trained in how to use them, I highly doubt many here are. Personally and for most of us, a cheap Jotter would work as good or not as good (depending on your level of expertise) as a $100 tactical pen.

A great tool that can be used for many purposes is a Starrett #18C Automatic Center Punch. It has a knurled handle which helps hands from slipping, a hardened steel sharp point, it can be used for breaking tempered car windows instantly, can CERTAINLY be used as a weapon just like a "tactical pen" and costs about $20 - 30 bucks used on ebay. It's AMERICAN made and can also of course be used for its intended purpose of making Center Punch holes for drilling.