Arecibo seems to me to be kind of a unique location and resource, but maybe the science of radio astronomy can achieve equivalent or higher resolution by using multiple smaller dishes and its more flexible.
STILL, I'm always inclined to repair rather than replace. Or, why not replace the entire thing, that sounds like it mightbe cheaper than repairing, especially if they could automate as much as possible of it.
This seems like an engineering problem that is likely fixable with a little innovation. An ideal candidate for a contest, "How would you fix or replace the Arecibo Radio Telescope economically" or similar. The winner and their family or a friend can get three free trips to Arecibo, and a party to be held in the winner's honor after the successful repair, as well as the satisfaction of having helped.
I would guess that there must be an answer out there, and its probably not as complicated as they are making it out to be.
Isn't that the whole essence of science and engineering anyway?