The worth of your Jim Beam decanter may be anywhere from $30 to $50. However, it may be worth more depending on the item's condition. If it is a liquid bottle, it could be worth around $15 or more. You may be able to receive more for the bottle if it is in pristine condition, which means all of the original material is in it and there are no visible defects.
A Jim Beam decanter can value between a couple of bucks, up to some thousands. It depends on the condition and year of fabrication. The best thing to do is start an online auction on eBay or Amazon and see how much you can get.