A couple of things in regards to shipping/Ebay.
1) The USPS recently changed it's shipping prices and went with a similar system as Canada. Meaning they now charge based on weight/dimensions and don't have the same flat rate as they used to. The smaller packages do still come in at set rates, but regular packages don't. So in time the US residents will be seeing similar rates to us for shipping. Which is actually worse for us.
2) If you are using Ebay, try and get the exact dimensions/weight of the package. You can put those into their calculator. That way anyone interested can check the cost of shipping and it automatically gets put into the invoice. It is calculated using Canadpost rates and you don't have to get quotes or explain pricing to anyone anymore. I started doing this a few months ago and can't begin to say how much better it makes selling on Ebay.
3) Paypal fees/handling fees. I personally don't like them, but they are a fact of doing business on Ebay now. I don't charge extra for them unless it has to be done. That usually only happens when special packaging is needed (post tubes, specialty envelopes/boxes). However, if the person is upfront about the extra charge, then I don't see a problem. You have the choice then to buy or not, but if they try to add it after the fact, then that is just scamming.