It's the buyer's responsibility to pay those custom fees. It's their choice if they want to import from US. (BTW, I'm Canadian) I'm well aware when I'm buying that any package that comes through might have the chance of getting slapped by customs for taxes and other fees.
But general...
Most items usually doesn't get pwned by customs, even if it does, it's usually just regular sales tax + like $4 service charge from Canada Post. (UPS Charges like $25 brokerage fees, no idea about FedEx, never got taxed from them before)
If you want to completely avoid taxes for your buyer...
So I bought a Plasma TV off someone from another forum. The price was a little too good to be true. ($1100 for a 42" Plasma HDTV ) BUT the seller was willing to shipped first. So I'm all for it.
Anyway, so it arrived today, very nicely packed. (And I mean NICELY, box was full of styrofoam...
I think what it means by trade including buy/sell/cross-trade.
On the major ones, chraging paypal fees isn't allowed. Anand, OCForum, XS, etc.
If you would like to avoid the 3% fees, apply for a personal account to accept non-cc paypal. That's free. You are allowed to have 2 accounts...