I can only share my experience here, I moved from Florida a few months back and have been second guessing myself eversince. Compared to the UK, the cost of living will be much higher and standard of living much much lower in Qatar. But that's the least of an expat's problems who comes here from Europe or North America. From bad healthcare to very expensive education to lack of rights to limited housing choices to worst drivers to bad parkers to overstuffed malls to lack of street signs to not enough for entertainment, everything will become a challenge if you kept comparing it with the UK. Give yourself a year to compromise. This place humbles you. What makes it easier to adjust here is the financial bottomline beyond your expectation. Since it will require you to leave your dream job, the worst thing would be you regretting your decision especially if the financial bottomline in Qatar is not really that good. I say, take a sabbatical if you have a choice and do a dry run. All the best.