I have a product timer product and configured per hour charges.

The Per hour Price is 25$

15 minutes will be given as grace if he late

If the Product is closed at 1 Hour 14 Mins, the charge will be 25$,

If the Product is closed at after 2 hours 14 minutes, then 50$,

If the Product is closed at after 3 hours 16 minutes, then 100$

Any help would be highly appreciated ?