OP,
I and 2 of my friends have done very well on canuckaudiomart.
Use PayPal for it's protection, and use your best credit card to pay paypal so you get the CC protection also. Seller may want you to split or pay the 3% paypal seller's fee they were not planning on, the protection is worth it.
You need an invoice for the item, i.e. 'goods' so you are paying for goods (protected) rather than sending money which is not protected.
Insurance: keep in mind, the seller is paying on your behalf, and if a damage claim, the seller has to make the claim, thus is is IMPERATIVE items are properly DOUBLE BOXED.
I had a bad experience, because Eugene didn't double box the unit, sadly destroyed, he gave me a full refund, but such a shame and it took a while. Got the one I have now from Vlad on canuckaudiomart, he is a master packager!!!
I would buy from Eugene, he had lots of great items, only after we had a conversation about double boxing.
.....................................
Another option, any item 'local pickup only' (any seller unsure about packaging): you pre-arrange and pay UPS to pack and ship to you, even from Canada. Find UPS office near seller, pre-arrange, seller simply takes unpackaged item to UPS in your name. UPS calls with the price, you pay them, they guarantee undamaged delivery. I just did it, worked like a charm.