That's a ridiculous amount offered and sorry to say you will be a fool to take it given your circumstances.

Own self do calculation, own self panic when they still lowball you.

TS, you are obviously worried you might be missing on some grand scale shit by not moving to the UK, but UK is also a shithole if you are poor there.

Given they couldn't even up your ask, that means your ceiling is going to be around £5-6k max.

If your position is as niche as you mentioned, it shouldn't be hard to push a salary of 20k in Malaysia or at least 12-13k SGD.

A 20k salary is easily better than a 5k salary in London.