While I've never owner a Ruger lever gun, I've seen them reach $700-$800 + in similar condition. Marlin 1894's in .44 mag are typically $600 - $1000, depending on the model, and they look more traditional, Old West style.
I think the new Remlin (Marlin made by Remington) is about $600'ish too, but don't expect them to hold value like an original JM Marlin. I'm not sure what year Ruger stopped making the 96, but that info is out there somewhere. I've got Marlin lever guns, but not Ruger. If I could get that one for $550, I would buy it, because I do own and love Rugers. Good luck with which ever one you decide on, I'm sure you'll be happy with either one.