Does this allow you to change the price dynamically though?
For example, if the user selects Canada for their billing address I must then add the appropriate taxes to the price dynamically. Doesn't seem like that is possible?
I'm afraid we don't support that use-case yet. If you'd still like to use Checkout, you could use it as a method for the user to add their card, and confirm the payment amount on a separate page. (the 'amount' field is not required)