Most employees don't directly contribute to revenue and are largely replaceable. Assuming their position cannot be eliminated, that is, the decision to have that position in the first place is reasonable, they are worth approximately what their replacements would cost in salary and training. Thinking of your worth as being largely determined by what another company might pay for you (or a similar employee) is generally reasonable, unless you're directly responsible for some portion of the revenue in ways that are not replaceable, which is true of very few people.