Additional user license-How much to charge

Hello,

Searched high and low and can't seem to find info on this.
What is a fair amount to charge for 1 extra user license to turn a
standalone app into a 2 user client-server app.  Is there a standard,
say a percentage of the 1 user price?  Two-user licenses are probably
not common but I want to work with this customer and at the same time
have a good sense of how to determine additional license fees for a
software product.

Thank you all.
Ed

If you want something easy to sell, price for value. Anything else is
largely arbitrary and hard to explain. If its hard to explain, its hard to
sell.

Depends on the market, your client, and a slew of other things. There is no
single correct answer.

Mark