I hope the equation is simple.
1. Receive payment then transfer it to your bank account [within 7 days]
2. Send payment using Credit card.
The only issues is, even if you earn $1 it should be transfered to your bank account with in 7 days. So obviously paypal will deduct Rs50/- as your transfered amount is less than Rs7000/-
You can not wait for your PayPal balance to reach optimal amount to transfer to your bank.