1. Bump everyone to $105k and ask if he's willing to take that number. If he's going to turn the job down over $5,000, do you really want him?
2. Offer him a $10,000 signing bonus and the same salary as everyone else.
3. Hire him at $110k but give him more responsibility-- including tasks that the other developers don't want to do, such as responsibility for 3:00 am phone calls when the database dies. How many people are going to complain about someone else making 10% more than they are when that "someone else" is taking on the worst projects with a smile and giving them more time to work on the good projects?
4. Discuss it with the team. Are they willing to hire this person at a higher salary than they are themselves going to get? Maybe they think he's quite good and want to work with him. Maybe they think he's not worth it. There's a lot of valuable information that can come out of this discussion.