I have entered these amounts where it says... handling (est. amount)
The handling charge is meant to cover packaging costs and rarely would be over $1-2. I do understand that some items would require complex, professional packing. But normally we are talking bubblewrap and tape here.
If you use Calculated for Canada, the Handling charge will be added automatically to the postage/shipping. So if it would cost $10 to ship your widget to me, I would see $140 as the Shipping and Handling charge. If postage to Alberta were $6.83, the Albertan customer would see $16.83 as the Shipping and Handling charge.
If you use Flat Rate for USA, when you go to Custom Destination and click on USA, you will be asked for the service you want to use and you will see a place to enter the Flat price of shipping.
A little lower you will be asked to enter the dimensions and weight of the parcel. Use metric measures. Canada Post went metric in 1974 and any other measurements will be approximate.
There is a small disconnect between the US and Canadian postal systems. In some services the Canadian minimum size is a little smaller than the US minimum size. The workaround is to add a centimetre to the Canadian sizing to make the match. Don't worry, this does not change the amount your Canadian customer will be charged.
If you don't do this, the US customer will be advised to contact you for a shipping price. Most will just move on.
And some unsolicited advice. As a new seller you are likely to attract scammers on high value items. It would be best to build your feedback with buying and sell lower value products for a while until you find your feet.
You do know that, because you are a new seller with no track record, Paypal will hold your customer's payment for 21 days against your good customer service, eh? Another reason for making your first sales (of many, I hope) low cost items. Less stress.
