The last order I had, Craftsy charged tax and it was sent via postal service, not delivery company. No extra charges. I had one instance that an order (cannot remember if it was Craftsy or another store) sent an order via delivery service and I was charged an extra fee. I made a point at that time, of always checking how the package will be delivered, before placing my order.
BTW, if you are ordering a kit from Craftsy, be aware that there will be NO extra fabric. If the kit says 1/2 yard, you will get 1/2 yard and not a thread more.
Also, when I picked up the order at the postal office, the lady behind the counter told me that taxes/duty are now routinely being collected on almost every order no matter how little it costs.