I recently won a bidding on ebay. since is a big stand, I am thinking about going down to pickup. Just find out that if i pay by paypal, i have to pay the sale tax when i go pick up and come back to canada to pay another 2 taxes.
if i pay by visa, i have to add 3%and sale tax, and canada taxes.

is that common that people charge 3% if paid by visa? first time i heard that

Visa charges merchants anywhere from 2-4% of a transaction for the privilege of accepting their card. It is pretty common for people to charge extra if someone pays by credit card, although it is probably in violation of the merchant's contract with Visa. Most stores that accept credit cards already have this extra fee built into their prices, which is why some smaller merchants will give you a discount of 2-3% if you pay with cash.