Ok, here is a challenge for all of us, me included.
What is your limit. How fast, dark, big can you handle?
Before any of us buy anything new, we really need to find out how much we have. I am as guilty as anyone here, often “upgrading” unwisely, sometimes even managing to go backwards while thinking I was going forwards.
So, using your best technique, software and lens, how dark can it get before you need to take “serious” measures (tripod, long exposure etc)?
How fast can you focus or more to the point how well can you capture a really fast subject?
How tightly can you crop your files that have the best subjective quality, which will help indicate how big you could print if you had the means and then ask the question, “do I ever need to”?
All have levels from lens quality, technique, software and processing, so explore the options.
Sport has been shot with single frame manual focus cameras. People have hand held medium format film cameras in near darkness at ISO 64, billboards have been made for Times Square adds off 8mp jpegs from older APS-C sensors.
You may surprise yourself.