For me in that situation I would give them my crazy number. If they accept, your happy no matter what. It could just be the beginning of a negotiation, which could lead to almost being the crazy number. Benefits play a huge part, if they aren't on par that needs to be made up in pay. Toss the crazy number at them to see how they respond, worse case scenario they shoot it down. My reply would simply be " you asked for a number to get me to leave a job I wasn't interested in leaving, I wanted to see how serious you were". If it backfires you just go back to the job you are already happy at. Win win!