In the condition shown...assuming they're in good working order...I'd expect you to find a buyer at $550 to maybe a bit over $600. The Pachmayrs one the one are aftermarket, I assume, which would hurt the collector's value, and the other one looks to have a bit of finish wear.
Very nice ones may go a bit more, but not a lot more. One recently sold for less than $700 on GB and it looked like new-in-box.
The stainless version (stainless slide, alloy frame) brings better money than the blued.
They're a good little pocket gun (I carry a stainless one when the weather is hot and my clothing is thin), but there are more modern, arguably better choices in lightweights for less money. You'll also find few 'smiths who know how to work on them (see Cylinder & Slide), so it's not a base for much customization.
These are really most attractive to Colt collectors.