Hypothetical to the larger HN community: If you got accepted a job offer, and within 2 weeks got a job offer for more money, and at your dream company, would you feel obligated to stay with your initial decision? If you made the rational (but arguably unethical choice), do you think your reputation should be tarnished, and future employers think hard before extending an offer? I know it's not the exact situation as t…
Your current best offer will be willing to stretch out their offer for a week. And the other company will be willing to accelerate their decision process, so as to bridge this two weeks gap.
But once you made your decision, you should stick with your decision... at least for a year, all things other than this 'dream job' being equal. The dream company and the dream job-- if you got in today, you are likely going to get that again in a year.