If you are underpaid yet comfortable at your current job, would you quit? What factor does money play in your decision to stay or leave?

Actually it depends on person to person, for some top priority is "respect", for some it is "power", and for some others "money".

In this question before deciding whether to stay at your current job or change the job, you have to ask yourself two questions:-

(1). Is another job which can give you a better salary + respect available?

(2). Are there any chances of growth (career growth + increment) at your current job?

** If the answer for (1) is YES & (2) is YES then don't change your job

** If the answer for (1) is NO & (2) is NO then don't change your job

** If the answer for (1) is NO & (2) is YES then don't change your job

** If the answer for (1) is YES & (2) is NO then only change your job

Money is not a factor for me but job satisfaction is!

Of course money are a crucial factor because so many aspects of life depend on them. If I was underpaid but safe in my job, I would search for another opportunity. If you live in a growing economy then it's the best thing to do because you can find something else that can give you a better future as a professional. So, I would have my eyes and ears open!

money has its own value which can"t be ignored, underpaid employee never be satisfied s/he always looking for switch or better opportunity, only motivation and respect can temporary increase stay. organization facing high turnover in lower staff is main reason that they feel underpaid.

Job Satisfaction cannot be paid by money. What is the point of getting a higher pay if you are not happy with your job and its environment, you will always be unsatisfied and keep looking for a better one. 

No I will not leave in as much as there is a bit of respects

Yes, I'd leave

No will not leave untill I get a similar opportunity with better pay, Money is important if you are underpaid you are not motivated , If it as at Par with the market standards just a variation difference then no point in leaving.

sometimes its better to keep going at a lower pay if you are getting good challenging tasks & future growth is higher.SO better stick with a lower salary and grasp a chance when opportunity comes wid good salary and good career prospectus. 

I do work with full enthusiasm but if i am paid less than market rate then definitely keep on looking for the opportunity!