Yea you can use ammobin.ca for ammo shopping. Some places will even ship free if you are over a certain $$ amount. Makes ordering online easy that way. That said, I bought 200 rounds from Ontario a month ago, and only paid $32 for shipping to BC. Was a bunch of 142 gr match king in the 6.5 CM.
I am in the process of building a 6.5 CM for bench work, and couldn't pass up a great sale price on the ammo. I still don't have the rifle built, but have all components and now factory ammo for when I start off. I'll be using a 26" barrel with brake, and tuner. Weighted chassis, so the recoil will be negligible.
Save all your factory brass for either reloading when you start, or you can sell it and recoup some of your costs. I have good brass already for reloading, so the factory brass will be good trigger time, settling in a new barrel, and then the brass sold off.
I have a 6.5 PRC for hunting with, and the CM is way less recoil. Should serve you well as a starting point, then work from there. The option of using small rifle primer brass is also a go on the 6.5 CM, and still accessible primers, so I would start building up stock for reloading, as you will save $$ for the amount you will want to be shooting over factory rounds. Bonus is you get to play with custom loading to really dial in your rifle.
It truly is easy to reload, and there is now a vast supply of great utube video's on reloading. Yes it takes some time, so that would be a consideration, but it is not a time waster by any means. No need to pay for classes. That said, if you have a chance to sit down with someone locally and watch what they do, ask questions, it will truly be helpful. Most guys are okay doing this as well. Heck some would even let you use there equipment, and you just provide the dies and components. (primers, powder, bullets) Most of the reloading community, and that said gun community are awesome people. I started to reload for myself just over a year ago now.
I'd probably bank on 1000 rounds for your first year, to get you some good trigger time, and still be in some shoots.