Oh, it's quite possible. My first hauberk was 40 pounds in weight, because it's 3/8" ID 14ga galvanized steel butt links. If it were made for someone bigger, or designed to hang longer, it could certainly reach 50. But you're right, you really don't want that. No one knew any better 10+ years ago, but now there's not as much excuse.
The jousting harnesses can justifiably be quite heavy, since the the horse carries the weight for you.
I think most of them tend to be in the 70 to 100 range, including the helm.
My plate harness is currently about 75 with the helm and gauntlets I added recently, and it's not complete (I still need greaves and sabatons, and I need to get my mail standard put together).