Well first off, you should know that different watches are different prices. The brand, model, make, condition, and year made all factor into this decision. Watches which include the original manufacturer papers and boxes can fetch upto 15% more cash for a watch without any of this documentation and materials. This is because when we re-sell the watch the buyer feels more comfortable with a watch that includes old warranties, boxes, and papers.
So there you have it, if you have a watch to sell... just check for the boxes, papers, and anything else that came with it.. it could get you a few extra bucks !