My rule is this basically for the games.
What ever is official is official.
If theres no written rules about your retal rules then no one needs to follow them.
If you are trying to net as efficiently as possible and want that win, you'll take any actions that logically help you win.
People take massive hits all the time, fluff happens, it's more than likely that the turns u've used from all the land is going to have benefited you more than the money required to retal you.
http://www.eestats.com/express/oldcountry/507/42
CX won last set and got hit for 2.3/3.6.
Even if you don't like his 1000 hit (which wasnt even that bad considering he's a tyranny) what do u expect a fair retal to be?
You hit him for 100 acres, even if he immediately took his retal blasting all his turns and wasting them he'd have gotten you for around 800ish anyways!.
In my personal experience, if you grow fast enough, I probably won't retal because it's just too costly, not everyone thinks rationally, but if you are a person who does rather than doesn't, you'll come out on top pretty much everytime. If that person does take their retal at least you know they won't finish well.
Would you rather have everyone immediately retal guaranteeing that you never place well or maybe 1/20+ hits gets retalled?
Might as well move to Alliance then if you want these types of rules.