Hi Gary, I would really consider doing it.
Here are just a few benefits (IMHO)
1: you get to practice your craft.... as mentioned earlier, use some inexpensive materials like mentioned earlier (files, RR spikes, saw blades etc etc)
2: you get to try out some different designs.
3: you can get feedback on your product (pretty important)
4: if you can sell them at a price to cover your supplies (and make a little for yourself as well) You are looking good. As mentioned above, the gun show crowd doesn't like to spend a lot of money on custom stuff. Think of selling at a gun show as a bit of an education.
5: you get to talk 1 on 1 to folks who are (or can be) interested in your product...
(dealing with customers lets you know what they are ACTUALLY interested in)
Lots of times we think we know what the customer wants and we can be way off. Selling your product and getting feedback this early in your career will make you a true knife making veteran in a very short time.
Best of luck and please post some pix of your blades at the Show (if you decide to go)
-Martin