Well, the SAKs are nice knives and generally available in the $15 range. Normally I'm leery of cheap knives- that's something I feel strongly that you shouldn't skimp on. That said, I know that not everyone can drop $100 on a
Spyderco or
Knives of Alaska folder. For many it will be a cheap knife or no knife. Personally I'd much rather have a $15 Mora than any $15 folder, but of course not everyone can legally carry a fixed blade, either.
For EDC at the $15 mark I guess a SAK would be my suggestion. If you can stretch the budget even incrementally you can start to get something a bit better. If you're gonna use it a lot I think you'd be better off with an appropriately sized Spyderco or Kershaw. My EDC knife is a
Spyderco Ladybug 3 in Zdp189. It's literally scalpel sharp OOtB. And while it's just over 2" folded it's actually very usable and feels good in the hand. A
Dragonfly 2 will offer more capability yet while still being very easy to carry. I'd consider the
Spyderco Delica to be the largest knife I could tolerate in my pocket for EDC.
For just under $30 it would be hard to beat the
Spyderco Persistence. It's between the Delica & Dragonfly sizes and is a very nice design.
In the Kershaw line I'm very fond of the
Leek, Chive, &
Scallion. As compared to the Spydercos they're somewhat heavier as since they have metal scales. The Kershaws open faster than the Sypercos (IMO) but are somewhat slower to close. Spyderco has the edge if you're into exotic steels; they offer many advanced steels like CPM-M4, CPM-S90V, ZDP-189, etc. In their smaller knives you can get S30V, VG-10 and ZDP-198. With the Kershaws you're limited to generic SS on the low end to Sandvick and D2 on the upper end. Still, at the $30-ish price point the knife steels are pretty comparable.
Please note that I didn't comparison shop for the best price- the links are just to the first hit I got at Amazon.com. Most of them have cheaper options than the ones listed.
At any rate, that's just a knife geeks $.02 worth!