Yup, Spydercos are great knives. I've got some Delica 4 FRNs that I really like.
I can't tell for sure what you've got there, looks like it could be a Delica. Blade should be 3" (with tip...

). If it's longer than that, it's an Endura. The pocket clip on the early models are molded from the grips. The original Delicas, before the plastic handles, had metal panels, I believe.
For $3, I'd say you got a helluva deal. New Delicas are going for somewhere in the neighborhood of $70-80.
If you're handy and have the proper tools, you could probably reprofile the tip if you want. Or there are shops that can do that. I had one of my Delicas reprofiled to more of a semi-Wharncliffe shape and shortened to 2.5".