Attribute is Free When Product is Free?

Hello everyone,

So I am helping a client fix a problem with there paypal checkout today when they try and check out with a free product they keep getting an error, I found out that it was because the dollar amount was set to $0.000.

This is how we have the product is setup now:
Under the product's settings the Product is Free is set to No, and Product Priced by Attributes is set to Yes.

Now on the Attributes Controller for the same product we have a drop down menu with a list of Attributes with prices but one of these we want to make free... it’s a Free Sample. The only thing the client wants to charge for during check out is the cost of shipping.

How do we set one attribute to free for only the Free Sample?

The only other thing I could think of was to set the product to free and then set Attribute is Free When Product is Free set to Yes, is this right and will it steel charge for the other prices in the drop down menu?

why don't you try that, you can create a customer account and try to checkout using the different methods. Try keeping the settings in the product page the same then just add price to the attributes that will cost money and the one that is free either insert 0 for the price or leave blank and see what happen.