An interesting question John. One that - notably but not only -Evan and I have kicked around for awhile in numerous conversations over the years.
It is this matter of identifying a subject transaction and fencing what you call 'speculation'.
While I can find good reasons to apply reasonable restrictions to use, I struggle with the notion of restrictions on pricing that would not offend my sense of equity.
The origination of the domain name market makes it even more difficult to find comfort advocating caps for second market transactions where choice exists in the market.
Carlton