Ask for $15k more and after some back and forth, offer to meet in the middle at $8k more. Working in your favor is the fact that they already know you are good

Ask for $15k more and after some back and forth, offer to meet in the middle at $8k more. Working in your favor is the fact that they already know you are good and that you are a good fit. By hiring you, they are also saving the time and expense of a lengthy candidate search, interview process, and 20% recruiting commission.