How do box and paper affect selling prices?

[GOB]

Say you are interested in a watch, but it has no papers. How much does value drop versus one that has papers?

Same thing regarding the box. If the watch does not come with a box (usually means the papers are missing too), how much does value drop?

This for a "regular" Rolex, not some limited edition or rare model. In my particular case, for a 116518 (YG Daytona on strap). This watch is proving to be harder to find than expected and the one I found has no paper, but the seller wants a price that is in line as if the watch did in fact have papers.