Selling on Agon question

Agreed, ONLY a wire transfer.

Also, forget UPS. UPS is a nightmare to deal with when you try to send or receive a package across the border. I've had packages get hung up for days, weeks, and even months. In addition, you'll take a bath for the fees, which will continue to trickle in for months and months.

Go with FedEX, they're much more straightforward to deal with. If the item's small enough, the Postal Service represents another option.

Both FedEX and USPS will treat you better than UPS if there's damage to the package in transit.

You can only Cash Money orders at the post office if the money order is an official United States Postal Service money order, which you can only buy at the post office.

If I sell something or buy something it the only form of payment, other than cash, that I prefer to use.

I don't believe the post office will cash just any Money Order.

Unfortunately, since it's a cross border transaction, the buyer is unlikely to be able to get a USPS money order. Wire transfer is the way to go. If it can go USPS, you may wait an eon or two to get paid if there is a claim, but you WILL get paid. However USPS only insures up to $700, at least that was the limit when I sent something to Canada several years ago.

My personal feeling on this subject is avoid international transactions altogether unless you're prepared for all the potential hassles.
BTW: I have cashed Canada Post money orders drawn in $US at USPS.

I believe you are also safe if the buyer sends payment via Paypal as a personal payment, for which there are no fees within the US and half a percent for international payments.

For shipping, Fedex now quotes prices including customs brokerage fees, which are reasonable and can save buyers surprises on the receiving end. Note, the service includes the brokerage fees, not government duties and taxes which are usually paid after shipping on the receiving end before or at delivery/pickup.

One last thing: I place no faith in the PPal Buyers Protection Plan. I had to initiate two claims, one for an amp that was never shipped (as verified by the seller), and one for an amp that was not functional on delivery, and Paypal was useless in spite of ample documentation. If the seller drains their PP account, PP can't do a thing for you. Fortunately I paid with a credit card.