This link will help you to compute how far your 5gb take you.
1GB = 1024 MB
Most of your activities are possible with Globe 5gb allocation.
For GoSURF Plans 99 to 999, the bill cap is P1,500. If you exceed your allocated MB's (1024MB x 5) you will be charged P2 per MB but you will not be charged more than P1,500. Once you hit P1,500 usage will continue as usual, but charging will stop.
maximum bill that you will get is P1,500 if you consumed more than 5GB.