Pricing based on whether user is logged in or not

I'm trying to create an event registration form where a logged in member gets a discounted price.

Basically the product will have 2 prices. $20 for club members and $30 for non-members.

Is there a way to set it up so that a logged in member only sees their price and/or make is so that a non-member cannot choose the members price.

WooHoo!!! It Works

For anyone reading this that isn't a developer (I'm not and it took me a bit to figure it out), here are the steps.

1. took the code from the link provided above and inserted it into my functions.php file.
2. added a Custom Field to my gravity form (I called mine "User Role")(This was the KEY to making it work)
2a. in the Advanced tab:
2a 1. checked "Allow field to be populated dynamically"
2a 2. Parameter Name: = "user_role"
3. In my product field (Member Event Ticket), I enabled conditional logic to:
Show if Any User Role is (value = "administrator") then I added another for User Role subscriber. (I wonder if you can make the value "is_user_logged_in")
4. in my other product field for non-member tickets, I enabled conditional logic to Hide if Any User Role is (then used the same values as I did in #3)

Thanks Rob, You sent me just what I needed!