My husband was burned by UPS when he purchased something through Ebay from US. The brokerage/custom fees were $50.00 on an $11.00 item. I've purchased about a handful of things online and have been okay, but all my items were mailed through USPS.
with regards to customs:
Putting "Gift" on package does work to not incure charges but a lot of stores don't like doing that because its lying.
If the products were made in the US, Canadians are not charged customs. I've been able to use this a lot as I get a lot of books online.
I will not purchase from a company that will not send via USPS. I just made a purchase and had to have a PO BOX to ensure USPS as UPS cannot ship to a PO, they take it directly to the door.
Its a live and learn world. I'm sorry for those that have bad experiences.