70,000 won't leave you on the breadline and although
condos can go for huge monies here, you could consider a HBD flat, which means there is no pool, or tennis courts, and such, and the rents are much cheaper.
Also we payed $120 for utilities last month, because we don't turn on the AC except when we go to bed, this includes gas/electricity/and water (PS you pay a fee for every toilet in the flat) so less bathrooms are better.
And I would say you could almost forget about getting a car unless you are willing to pay over the top, a cheap car here is considered to be $50,000 and then you have to get insurance/tax and a gas at more $1.30litre (approx).
My husband was offered lower that his UK salary to which he held out for more and ended with 30% raise.
If it is a UK company you should argue for more money on the fact that the local sales tax (equivalent to VAT) is set to rise to 7% (currently 5%), it will cost your company less for you to work in singapore because of lower employers taxes, and it is a bit unfair to expect you to take a pay cut and let them send you half way around the world.
Also be sure they cover a moving and medical expenses, it is very expensive here to see the doctor and they should supply accommodation for your first month, until you find somewhere to live, and give you a moving grant which helps you set up home. ie paying deposits (Utilities $500, Phone/Cable $300) and you will have to pay 2 months deposit on the flat. Plus furniture and you will probably have to cover your air con maintenance.
And of course clothes, cause it is freaking hot here compared to the UK *lol* and the clothes are cut to asian sizes, so if you are broad in build clothes are going to be hard to find.