FX is a huge rip off. I have just started a transfer wise account which gives you a physical debit card (mastercard) and virtual bank accounts in USD\NZD\AUD. The difference is that when you do the FX transaction it's 1% fee instead of the normal 3% the credit card company (or Amazon).
If anyone is keen this invite code will get you the first transfer free:
TransferWise is nowhere near as great as you think it is as a payment card option (but is great if you want to transfer currency).
Banks don't charge 3% so I don't know where you get that from. For NZ banks the typical forex conversion rate is around 1.6 - 2.0% now, with ANZ (who I use) at 1.8%
So Visa / Mastercard convert to NZ$ at a rate which is very close to the mid market rate, and then ANZ add on a 1.8% fee. I then get 1.3% back as Airpoints Dollars giving an effective rate of 0.50%, vs the hassle of using TransferWise and paying 0.49% - for 0.01% it's not worth the hassle.
Using any of the "charge in your home currency options" whether online via Amazon / PayPal or at a terminal overseas is a guaranteed way to get ripped off - you'll pay several % just for the convenience.