Are there caps on any other purchases out there?

Should we start capping the amounts that startups can be acquired for? If FB is willing to pay 1B for Instagram, 19B for Whatsapp, or more - who's to say that they can't spend their money the way they want to?

Well, if we start treating domain names as a public resource, then caps might start making more sense. It's like any other regulation.

AFAIK, there are regulations already for how much you can pollute your environment, usage of rivers, height of buildings, rearchitecting your house etc.

A cap would be impossible to enforce; ICANN can't monitor someone forking over the cap + a briefcase of cash between two buyers god only knows where.

And super-valuable domains are minuscule portion of overall domain sales, it simply wouldn't be worthwhile.

And it need not be a "sale of a domain" at all; it can be the sale of "ww.com corp", which owns the domain, without any domain transfer at all.

For one caps are absolutely non-enforceable, second it would be setting a pretty bad precedent to retro-actively set a cap on something long after the trading has started. I'm not aware of a precedent like that. Imagine a cap on land prices. Or a cap on gold or any other good that is freely traded.

Next thing you know you're going to have to declare your 'five year plan' when you register a domain...