Discount on Internet order

Ok so I've been told by an audio vendor that only foolish vendors who don't plan to be in business offer discounts. On the other hand a vendor from Eastern Canada regularly offers me 20% off retail. Lately I've been looking into a new component. It retails for $20,000 Cdn. I found it new in the box for $15,000 US. Then I found a US vendor offering it at a discounted price of $10,000. I asked for a firm quote. In a written quote they offered it for $8,500 including shipping and insurance. The interesting part is that they were shipping UPS and the quote showed Cdn taxes of 12% of $5,500. I asked if the full $8,500 was insured and the vendor said yes. The tax was based on $5,500 because he was insuring it so the value for insurance was his cost, not my price. So on a $15,000 US item this guy's cost is $5,500. Seems like huge margins are available.