This could be done by the Internet Archive.
Assuming a long-term return of 3%, in exchange for a $200 one-time donation, they could afford to spend $3 a year on maintaining a page and get another $3 a year to fund their operations. Right now, that's enough for 2GB of disk and more cpu and bandwidth than will be used long-term.
The biggest costs are likely to be customer service and abuse prevention. That could sink this.
That's changed, as of 2017:
A few months ago we stopped referring to robots.txt files on U.S. government and military web sites for both crawling and displaying web pages (though we respond to removal requests sent to info@archive.org). As we have moved towards broader access it has not caused problems, which we take as a good sign. We are now looking to do this more broadly.
We see the future of web archiving relying less on robots.txt file declarations geared toward search engines, and more on representing the web as it really was, and is, from a user’s perspective.
https://teleread.org/2017/04/24/the-internet-archive-will-so...
https://blog.archive.org/2017/04/17/robots-txt-meant-for-sea...