Price by Member Group Fieldtype
Overview
The CartThrob Price - By Member Group fieldtype allows you to create multiple prices which depend on the member group of the customer.

CartThrob Price - By Member Group
Add a new CartThrob Price by Member Group field to your Products channel
Head to Admin > Channel Administration > Channel Fields to add a CartThrob Price by Member Group field to your Products channel. You may, in fact, want to create a separate channel for items that are priced by member group and map it accordingly in your CartThrob product settings.
Variables
If your field is named "price", you would output this field as "{price}"
{your-field-name}
This will output a formatted number (eg. $10.00) that is specific for each member group. When the item is added to the cart, CartThrob will know which price to use based on the member group of the logged in user.
Important Note
This field accepts numeric values using "." (english standard) as the decimal point. Even if your locality normally uses "," as the separator between whole numbers and fractional amounts, you must use a "." as your separator when entering your price. On output CartThrob can convert this decimal point to any other separator, but on input, english standard decimals are required.