I think a lot of it depends on your age and what responsibilities you have at your current job and what you will do at the new job. If you're young, like me, I put my priorities like this:
1) Challenge/Responsibility/Opportunity - does this position offer me an opportunity to make a step up professionally, to advance my skills, to challenge me in a way that there is a real risk I'm exceeding what I'm capable of?
2) The work itself - is this something I'm interested in pursuing or will have any relevance for my career going forward?
3) Culture/lifestyle - what is the work environment like? The location? What might my personal life look like?
4) Compensation - do I get enough vacation not to burn out, can I save some, not live in the ghetto, etc.
I'm in a similar situation. Looks like I might have lined up a job paying around $36k, a definite step up from my current salary but because its a much smaller company and the role isn't clearly defined there is a lot of risk involved. But I have no wife/kids/house, am 23 years old, and this is a clear step up (from production worker to production manager), so screw it if I'm miserable for 2 years it is still a good opportunity.
As I get older, my priorities as listed above will likely be in the reverse order.