I have been playing with the idea of a FF camera for a long while. Although I do love my 7D cameras, my 70-200mm f/4L IS lens is too tight for some of my dog portraits because within the space in which I shoot, I cannot get back far enough to cover a relatively larger dog at 70mm. Additionally, my 17-55mm lens at 55mm is not quite long enough for tight head shots without getting too close with the risk of distortion. My old 28-135mm f/3.5-5.6 IS lens would be a good focal range but the IQ is not quite what I desire. I figured that the full frame camera with the 70-200mm lens would give me a bit of leeway.
I found a Canon 5D Mark II on eBay with about 15,000 actuations at a very decent price. I figure that I can play with it for a while and if I like it, I will keep it. If it doesn't suit me (or is not worth the price to me) I can sell it without losing much money.
I priced renting this camera and I know that if I want to resell it, I will save money by going this route...
I didn't want to go to the expense of purchasing the Mark III version which would have cost almost twice as much as what I paid for this camera. The Mark II (in fact even the 5D Classic) would be good enough for what I want to shoot with it. The camera is being sold from a seller with 100% satisfactory feedback for almost one thousand sales.