[Baalz]

Yeah DC, I think this is thinking that will trip up a lot of people trying to do this with CW. In the vast majority of Dominions play this is exactly right, gems collecting dust are essentially wasted. In this context though those gems are being used just sitting there - or being dumped into your globals. Look at it this way, if you are in a situation where you're contemplating putting 999 gems into the spell (or any large number), you're going to be ruling a large nation with by that time a very well established dominion. Think of those large amount of gems as buying tens of thousands of vine critters over the course of many turns and it starts looking less like a waste- particularly when you factor in the gem income and account for mother oak's income in the same accounting bucket.

The way I see it, if you don't use those gems as an insurance policy then CW being dispelled goes from "maybe eventually" to "almost certainly, soon". As soon as you're a credible threat to anybody from mid game on dispel is going to be at the top of their minds, and it's much more difficult to get back on top of that fight after you've lost the gem income from the globals. In this case, I think it's prudent to win the fight before it happens. The other way to look at it is 'am I better off with CW up or with some extra N gems?' If you answer that question differently than I did, you might want to skip CW altogether.