Customize Shipping Method Based on Payment Method

[chintanpkamani]

Need to basically customize the shipping rates shown based on the payment method chosen.

I have 2 payment methods 
- Online
- COD

If payment method is chosen Online
- for orders above 500 no shipping free
- for orders below 500 - a small fee of 100 

if payment method is chosen COD
- flat shipping fee of 110