I agree with the others, I would go for a full rack over a half rack to provide better safety for squats and bench. Technically, you could shrug off a failed squat, but I wouldn't want to do that in my house unless I set up a very solid platform under my rack (a very good plywood + stall mat build and if you're doing this in your house, new stall mats reek for a long, long time). Similarly, if you don't use collars, you can dump the plates on a failed bench, but I'd rather not do that to my floors without solid protection.
Used is definitely the way to save money, but you could get a similar setup from Titan Fitness or maybe Rep Fitness for about $1k new. Skip the 15lb plates, but get some 5lb, 2.5lb and change plates. I like microgainz.com for change plates, but I'm in the US and don't know how shipping to Canada compares.
lol [https://en.wikipedia.org/wiki/Military_grade](military grade). I never gave this much thought until I bought some "military-grade" weight plates for my home gym. They were FAR lower quality than my other plates, but also cheaper. This isn't even a matter of "which" military, this is a matter of the cheapest thing that technically meets standards.