Auditors, with bachelor degrees, start off at BIG 4 at $2,500pm.

Typical Uni degree takes about 3-4 years. Since you are diploma with 1.5 years experience, I think you are overpaid. should be getting closer to $2.2k.

Auditors in Big 4 can be considered "front office", since their roles are closely related to the revenue streams of the company.

Your role as a finance executive is ancillary, support, "back office". Another reason to consider.

Bottom-line: Just go interview and if anyone offers you a higher pay than what you are getting = you were under paid, vice versa.