You can get a more accurate answer using
ebay, either browse by category or search. Once a search is done, sort by price from highest to lowest, including shipping if looking at low priced items. Then, and this is the key part look at completed listings to see what sells and what doesn't. Looking at sold listings is also effective, but won't give as good a feel for what types of listings rarely sell.
Sometimes finding group lots of stamps as opposed to individual listings may be difficult because sellers don't categorize very well. Individual stamps are often found in categories related to lots and collections. Why sellers place them there is not clear. But, many
ebay sellers are lazy.
Clark