28k is plenty but It's not a big salary for those coming out of college. In Connecticut where I live average tuition is over 20k+ a year. College is a pretty massive debt if your only making 28k a year.
Anyways, as long as you don't own a house and rent 28k is more then enough to live on. Between me and my wife we spend less then that a year (though to be fair only one of us drives, driving is a big expense here in the US. $600ish every 6 months for car insurance, $20-$30 a week on gas, car maintaince then the fact you gota buy a car every 5 or 6 years, at least we do)
It's just that simple.