Hi guys, can I ask if my payout is OK for my exp and degree?

Job Title : RnD Scientist
Job Desciption : Research on electronic motherboard
Age : 28
Years spent in company : 1 yr
Industry : Engineering
Tenure : Permanent
Experience before joining (years) : 0
Highest paper qualification/ education background : PhD (yes I have 0 working experience before that)
Location : SG
Average Working Hours Per Week (incl lunch hours): Very flexible. Official time stated is 9-6. But usually I log out at 4-ish. ...as long the job is done on time, can leave early.

Monetary Payout:
Basic Salary + Fixed Allowance : SGD 4400 + 13 month bonus
Benefits (where relevant) :
Health Benefits : Paid medical check-up, medical insurance
Transport Benefits : Claimable (eg. Grab etc for official work function)
Mobile / Internet / Gadget Benefits : SGD 100/month
Flexi Working Hours : Yes (<-- the biggest benefit of all?)
Other Benefits : None

I have a feeling I am slightly underpay at the moment. but then,  i have 0 working experience... and this is my first employer.  Opinion?