If the owner doesn't claim them, give them away to someone who could use them because they're probably not worth the trouble of selling.
There are around 50 flies there, so worth about $100 for the flies and another $20 for the boxes if they were new and unused, but probably only worth $35-50 for everything if you're trying to sell them as-is. Really depends if those are from a decent fly tyer or are mass produced crap from overseas.
I used to be a tyer and have lost a few boxes on streams over the years; it's something that happens and you just replace the stuff and move on. Flies are pretty disposable and get damaged easily so it's easy to just replace them (you'd usually have a dozen or more of each of those patterns if you're a fly tyer).