Not sure how you told them 3+k is enough over the phone - but maybe you can try asking for a 4+k package to cover cpf, medical, etc.

The danger zone part - every company is different - talk to your professor about the opportunity and also do ur own research - the forum can only offer general advice as we have no context. As an adult, there are times you have to make your own judgment and take risks. Nothing is certain or guaranteed - part and parcel of growing up. You are still young and can afford the risks. If you decide to go into it, give yourself 12-18 months, if it does not work out, then move on.

Good luck!