What I do is to keep an eye on some of the older Canon L lenses that are the most appreciated by photographers, lenses that are "previous" models, or without IS. For example, The EF 200mm f/2.8 L II (black color with the red ring up front) is relatively cheap, quite fast, and sharp. The same for the older 135mm f/2 L. The 100mm non-IS Macro is also very sharp, and well as the 400mm L without IS. Some of these lenses aren't produced any longer, but still sold at Adorama and B&H. yes, it's nice to have the newer lenses with IS, but I just used a tripod-if needed-with the older lenses.
This is a good place to find information about Canon lenses and cameras:
https://photography-on-the.net/forum/showthread.php?t=42034
