All is depending on the state the barrel is in. Can you put a picture here on the forum ?. Normaly these barrels have a value of US$ 150,- up to US$ 350,- but again, what's the shape ?
Best place to sell would be E-bay I think or here on the forum. Maybe I can help. Try to sell it local. Shipping world wide will be difficult. Will be lcl container loading I think.