I went for an interview yesterday for a Lab Technician in a school. I was the only candidate for the job and I was offered it on the spot. I said something like "Yes, but I need to discuss it with my wife first to confirm for certain" The same day I received a call about another job for a position in Research and Development for well over double the salary.

The Lab Technician Job doesn't start until September and I haven't completely accepted although I did give a very very strong indication that I would. Is it ethical for me to attend an interview for the second job? This only happened yesterday so could I phone the school and say I need more time to decide? If so do I tell them about the second job?

Any advice would be extremely welcome as I don't want to be seen as unprofessional but the extreme difference in salary would mean a completely different life for my family and me.