there is ALWAYS the chance that you will end up hating the new job just as much as the current job - maybe not right away, but it can and many times does happen.
You should always be "smart" about talking money in this situation. Leave it out of the question unless actually shown interest by the company in hiring you (after interviewing, not before) or hardpressing you for an answer, but prior to that I always state, "well, it depends on if you are interested in hiring me and I'd like talk more about the position and your company, and my future outlook there", etc - that can really impress/catch them off guard.
But in that case that you are hardpressed to give $$ numbers/requirements, you should be shooting high and being respectful about it. I would also be honest about what you currently make, as many companies now do very in depth background checks, even AFTER you are hired and if you lie about money - a substantial lie - it could cost you.
Figure for any good move, a 10-20% minimum increase is pretty much the low floor you should be looking for. Otherwise, if not about money, then whatever you feel comfortable with.
hell, I told a headhunter a while back I'd be willing to take a $5-10k paycut just to cut down on stress and get back out of management again.