Just as an FYI, my own favorite low-cost folding knife is the Ka Bar Dozier Folding Spear ($20).

http://www.knifecenter.com/kc_new/store_detail.html?s=KA4066

I bought them for my two kids (now 13 & 14 years old).

It uses torx-head screws to hold the clip and the thumb stud. I had to move both my lefty son.

Its a great low-cost knife.