As stated previously, there is more points here than just money and perl. Job satisfaction is another very large point. Another point about the potential job that you are turning down; longevity. If I am reading between the lines correctly, it seems that the new job would only be for as long as they need you, not for a permanent hire. Would the gaining organization just throw you away when they are done with you? Is your current employer going to do the same? I guess you really don't know until it happens, unless they tell you up front. I don't think that I would leave a sure thing (ie: year(s) of employment) for something that might end in a few months.