It's $10 usd upfront and then it depends on how you're using it. This is the chart from their site:

https://bitpay.com/card/resources/Fees.pdf

I'm going to go slow, do one transaction at a time & see what happens. The one thing to avoid is a 'not sufficient funds' - that's $15 usd per instance! Ouch!

I hoping to give it a test run today or tomorrow. Fingers crossed...