If its old (tackle box) and reasonably priced, I will generally buy the whole box and go through it later so I can move on.
I have found vintage reels in boxes, cash, early lures in original boxes bla bla. I have mostly kept the finds, rather than sell them.
Since I spend much of my free time at the RI shore, I am always looking for collectible or useable salt water items. Generally the “SALT” is very bad news for items. A few years back, I came across a sale on the way to work (nowhere near the ocean) that had some great items. A 1700’s house with original family members (descendants) still using it. Among the pile I made, were early salt water casting lures, unused mostly, in original boxes. Wish I had some pics. Yup, sold them babies. There was a very upset buyer looking through my pile as I was getting ready to load the truck, he thought he hit the mother load, NOT.
Happy hunting.