TA commission varies by country, in NZ and Australia it can be substantial (USD 500) for a OWE fare; in the US it is under USD100 (not sure of the amount, I don't have a friendly TA and am not in the industry, but it is small). Canada is somewhere in between. Some TAs will kick back part of their commission but given the amount of work involved that commission is deserved in most cases. I often work out the exact routing and dates, often even book it, and then give it to a TA. I used to ticket through the airlines but it has become more and more difficult to do so (CX in YVR does an excellent job, that would be your best choice in Canada if you didn't want to use a TA; CX will Fedex the ticket to you at no charge).
September is a good time to travel. Hope you spend a day in ANC, it is beautiful country and you can arbitrage the DFW/ORD flights (if both are still operating) to have 23 hour transit and thus not charged a stopover. Personally I would use one of the NA stopovers for ANC and spend a day (hotels may be more reasonably priced by September, all tourist things are expensive during cruise ship season). YVR also merits a stopover, if you haven't been before.