[eps]

Negotiations require two parties willing to negotiate.

In your example one is not, so negotiations aren't possible.

[chatmasta]

Successful negotiations require more than two parties. That’s the whole point. If you are only getting one offer then you are leaving money on the table. You need to “create a market” by getting multiple. And if you’ve only got one, then stall as much as you can to find another (which could be a counteroffer from your current employer).

“Negotiate from a position of strength” is evergreen advice.