All About Pocket Knives

I'm not very good with pricing fixed blades. I had a friend send me this picture and I can't even guess at what the price might be on any of them. Anyone got a ballpark $$$?

I don't want to appear overly negative about those knives; however, the middle one looks like a cheap diver's knife and the bottom 19" blade looks like a homemade something or other. Without having any other stamp information, maker, etc., I doubt they're worth anything at all.

David: the top knife appears to be handmade and from the style of the wooden handle I would think either African or Filipino in origin.The sheath looks like a WWII era piece.
The second knife could possibly be an inexpensive diver's knife;the stamp would bear this out.
The bottom knife also appears to be either of African or Filipino origin;the sheath doesn't look original.
The Vernco folder I have a couple of and I think I paid a few dollars apiece for them.

Thanks for your input guys, very much appreciated.

I will be meeting with this guy tomorrow to look at these knives and to help him with pricing them. I wrote a paper on the Bolo Knife a couple of years ago, so the only one I really want a close up look at is the bottom one. I need to see what the handle is or was to help ID it.

Thanks....David R