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I have a job offer from another company, with considerably more money than in my current job. The main motivation for accepting this new job is money, because I've been having health problems recently and I have been spending a lot, I'm afraid I'll be broke shortly if I don't find another source of income.
I like my current job a lot, and I don't like that much what I'll be doing on my new job. I was hoping to speak with my boss, he is very open, but I don't want to look unprofessional, and let him know my motivation to moving to this new job is mostly financial because of my health situation. Would this look unprofessional if at the end I decide to stay? Also I would be a huge loss for the company, I'm one of the oldest employee and all the technology of the company was designed by me. We have been always understaffed so basically I'm the only one who know how everything works.