I am often asked “what lens to buy”. One answer: rent. Renting a lens for a few days allows you to try it out risk-free and pressure-free.
And renting is possible almost everywhere, especially in North America. In Ontario, for instance, you have Henrys/Headshots and Vistek as two good options.
But a new third option also sounds interesting: GTA Lens rentals. Interesting especially because prices are lower, and they stock exactly the Canon (and Nikon) lenses (and a few third party lenses) that you are most likely to want to try out – all the pro lenses I own in fact, and then some. Worth a try, and I am going to rent the 85mm f/1.2 every now and then -my favourite Canon lens, and the one I do not own yet!