My husband isn't in your industry but he negotiated to keep the equivalent of his UK salary in Singapore - taking into account the tax here is 40% and in SG it's 22% (I think?) it's a VERY good deal.
Costs the company no more but he gets the benefit of the tax and company will also pay rent (S$15k per month) utilities and car rental.
Remember, they're offering YOU the opportunity so make it work for you and your family. The perks make it worthwhile disrupting your home life for.