You can get a pretty good idea of the value of these items on eBay. What you do is simply enter the item name, for example, "Forgotten Realms Cities of Mystery" in the eBay search box, click search, and then click on "sold" items check-box on the left-hand side of the page. Up came about eight or nine or so boxed sets that have sold over the past ninety days. Some sold for around $40 and some sold for less than $10! Study those sales. You'll begin to notice that informative listings by established sellers of high quality items generally sold for the most and low-quality, sloppy listings by sellers with poor reputations generally sold for the least. You also notice some sales that make no sense because they sold for too much or too little relative to other similar sales, but overall there is a pattern which will emerge. There are many variables. Learning what works best and what doesn't takes a little time to learn but no special training.
So, with the kind of items you are selling, not the uber rare stuff, you can find out the value of items on your own. Asking us to do something that you can do yourself is not what we're about here. Do some homework. You got this! You'll be better off in the end and know without a doubt what their values are!

Truth is worth finding and life is too short to work for money.