Kodak Retina Ia and Argus 270 value estimate?

Good Day APUGers!

I've gotten a couple cameras from my Dad and I wish to make sure I give him at least fair market value.
The Kodak is in fine working order. The lens are clear and shutter speeds sound right (will test with film when I get a chance). Bellows appear in surprising shape and I could detect no cracks or pinholes using the light in a darkened room test. It has a scuffed leather "Retina Ia" case.

Argus Instant Load 120, I need to find a new battery for it before I can check if all functions work. The lens are clear, focus and shutter rings move smoothly, don't feel loose or wobbly. As you move the focus ring a indicator inside the view finder moves from one side to the other (landscape to group to portrait). What appears to be a simple light meter on the top of the camera is not stuck (jiggles a bit when the camera moves, but I believe without a fresh battery, I can't tell if it works. It comes with a (I believe) faux leather case with "argus" embossed into it.

So people what do you think,? Anyone willing to offer a rough estimate, or a quick and dirty guesstimate?

I should add that the Kodak Retina Ia has a f2.8 50mm lens and is "synchro-compur".

Have you tried searching completed sales on ebay? There are often matches (or matches) there for cameras which would give an estimate.

Yard sale and thrift shop prices for either fetch $10 - $20 in my area.