let's put it this way:
if you're asking for someone' salary, you should say:
"How much do you make?" or "How much do you earn?"
if you're inquiring for a possible salary value from your new employer:
"How much will I get (paid)?"
if you're asking for a certain cost to be paid:
"How much is the pay (for)....?"
ex: "How much is the pay for a waiter in Singapore?"