jgold,

Your information is a bit skimpy for a definitive answer, but some points to consider:
1. there is absolutely no problem in having a Canadian travel agent assume your reservation, if that is your primary concern on this option. Using a travel agent is easy, since most will accept a US credit card and FedEx the ticket to you. This seems by far the easiest route, although some agents may charge a fee.
2. Have you checked the taxes, credit card fees, and costs for the positioning ticket to get to Santiago? If the saving over buying in the US is only $1,100 these may eat up a significant portion. Or did your cost savings estimate include these costs?
3. If you buy in Canada but do not want to use a travel agent, seems simplest to merely book and price via the RTW desk in US and buy in Canada at an AA ticket counter. Depending on where you are located, flite and perhaps overnight costs may be minimal. Be sure you can change an existing US credit card to a billing address in Canada; this may vary by issuer and some may view it as a significant change impacting card validity.


Best of luck in working this out. Please keep us up to date on how this results. It seems a creative way to reduce costs.