I'm currently going through my collection updating my documentation on what I have and I was trying to look up what they are currently "worth" (dangerous word that and value) but the only place I know to look is eBay's Sold listings, and if they have nothing I'm running into a road block. For example Iron Factory's Asura Knights (Dinobots) I looked them up and eBay is showing none as sold how ever long they keep them in the search. There is one set currently listed, and it will probably sell with 9 bids already, but if possible I would like more than just one sale to judge "value" on. Besides asking about each individual figure is there another option to find such information? Honestly that is an unappealing option because it will be both annoying for everyone and will be more of an opinion rather than an actual "it sold for this much" answer.
On the game show price is right, contestants start with $1 if they don't know, cause they can't go over.
A while back I did the same thing to get a value on my collection, but I'm afraid I also just used active and sold eBay listing to gauge the value. I only did the stuff I have on display, but I came up with a total value of about $12.5k. You could also use the search function on this forum to sift through the B/S/T forums to see what they went for here, but you'll likely see much better deals on the forum than on eBay. Actually, I searched the trade forum for "asura Knights" and came up with a recent set that sold for $250.
Many figures are impossible to get now, so some are literally priceless. I have a collection in the upper 5 figures based on lowest eBay prices. That’s what I go with for insurance purposes.