330/350 SO Base to begin with, on MGH, is about $107k a year. Overtime depends upon trips you do. Hard to give an estimate on that figure.
If you fly more than MGH, then it’ll push it up. But don’t plan for things that are completely within the control of the airline.
Allowances can vary depending upon base and type. Example being if you’re doing a Singapore, it’s about $400/day. If you’re in Jo’Burg, it’s only about $180/day (allowances are paid as DTA from sign in to sign off). Use $20-30k as a very rough guide.