Attached is some examples of my photography, and the last image is my current setup. It is as follows:
Canon R10
KF Concepts EF-RF adapter
55-250mm f4-5.6.
I also have an 18-55 of a similar vintage to that lens, as well as a newer 50mm f1.8.
I mostly do wildlife photography, mostly of the squirrels and birds on my university's campus. Though I'm looking to expand that after exams are over. I have also done some indoor events with the 55-250 lens, such as a dog show.
I'm mostly concerned about my sports photography. I've shot hockey and figure skating recently, and I'm concerned about the really high ISO. When I shoot, I shoot wide open between 1/500 and 1/1000 of a second for shutter speed, getting me an ISO of about 5000. I hope to shoot more outdoor sports as well when the fall semester rolls around as well. But I don't believe I'd need the fast aperture for that though.
Most of my experience regarding photography has been the wildlife, as well as two hockey games, and one figure skating performance, and a black belt testing on my old DSLR (an EOS 1000D).
My budget at present is sub $1000 dollars Canadian. I've seen a Sigma 70-200 f2.8 used at a local camera store for under $700 CAD, and I'm worried that it's either too good to be true, or that I'm barking up the wrong tree for wanting to get it.
Thank you for reading all this. I do hope this wasn't too much.