After two years of hemming and hawing and researching until nearly going blind, I finally bit the bullet and purchased a pair Leatt X frames. $445 USD. Had been running strap on knee guards, so they were not hard to get used to. Well worth the protection. An ACL or MCL surgery will end up costing far more. I think the X-frames bridge the gap between the super expensive braces and the cheap knee guards. I've been very happy with them.
I'm not getting any younger (45) and it seems every year I add another piece of safety equipment. I just started wearing a neck brace a few months ago as well. Soon I'll be covered in bubble wrap...