I am in Lachine and putting an 87 K75S back on the road.
If my experience is any example, costs will be higher than you think, we are in Quebec after all.
I've priced Bridgestone Spitfires at Pete's Superbike in Vaudreuil at $255 - tax in. From the states on the net it would be cheaper, but there might be shipping, duty and the $ exchange rate to factor in.
I'm doing whatever work that I can myself, and I would recommend that to you. It is a great way to get to know your bike.
You picked the right place to come for info. The folks here have a wealth of knowledge, and there is a lot of documentation available.
Digging around, you'll probably find that someone has already asked your question.
I've spent about $1000 so far and have done all fluids, fuel lines, filters, cleaned tank, replaced fuel pump and gauge, had the injectors cleaned in Pointe Claire, lubed final drive splines (Moly 60 is $30 here).
Good luck.