I need to add price for the customer group from magento admin so each customer group have a different price. I also need to show these group with group price on the customer registration page on the frontend so when some customer create his/her account he/she need to select a customer group plan after filling the form user will be redirect to the payment gateway like paypal for the payment of the selected group price after successful payment customer will redirect back to our website and this way his/her registration is completed. How I can implement this logic as I am new to magento. Any help would be appreciated.
Group price already available at magento and Group price is only set for products.
So you no need to extract code.If you will provide a customer to select his/her customer group at his/her registration time ,then whenever customer will purchase a product then product will purchase with that product's customer select group price.
But for buy a product with its group price then you should login at system
Also you can not go to payment with out cart a product