It is very difficult to make any money selling single books or a single pair of pants , a single shirt , a single video game , ect...
Unless you have a very hot item you should group together items of little to no value. You might be surprised that someone would want it.
If you have a single used romance paperback with markings and folded pages, it is worthless. If you have 50 of them you might find that you can get $20 for them. The same goes for used old clothing or games or anything else. If you have one pair of very used blue jeans it will never sell but if you have 5-10 of the same size someone will buy it.
You will never get more than $1 for an out of date sports video game but in a group mixed with other types of games you might get more.
This method usually works very well if you are patient. Just make sure you are very honest with condition.