You can certainly ask for a ball park figure, although a search on flea bay may give you a better indication. However if you wish to consider selling then you will have to post in the relevant classified section.
Or too little. Some dealers will offer a P/X but that will probably get nowhere near to selling privately. I don't have that problem, my son is like a gannet, I don't get the chance to sell anything.Yes, I understand - just didn't want to ask for something stupid