I think the "surplus effect" here would also be nice. If he was willing to accept $55k and you say, "tell you what, let's make that $75k because we really like

I think the "surplus effect" here would also be nice. If he was willing to accept $55k and you say, "tell you what, let's make that $75k because we really like you," you're going to get a very happy employee, because he perceives that you just gave him $20k he wasn't expecting. Whereas if he just threw out $75k and you said "fine," it doesn't feel like a gift. You could get a similar, cheaper surplus effect with all your employees by throwing in perks. "Now that we've agreed on salary, we also want to give you an extra personal day each month," or a laptop, or a trip to a conference, or a weekly lunch, or something else that's nice but not incredibly expensive.