How vital is it to trash Estates in the early rounds of a Dominion game, given that there is an action card available to trash Estates?
Multi-card trashing, when available, is usually the best way to open the game. Indeed, as The Chaz says, you want to get rid of your coppers as well your estates.
Trashing with single card trashers like Remodel and Develop are less pressing and often not the best opening.
As with all games of Dominion, it depends upon the Kingdom Cards available. Estates are no help to you in the early game (barring a Baron or similar card). Trashing them will increase your average Coins per Hand, and make it easier to by more expensive cards, especially those in the 5+ range that tend to be better.
If you have a card that can trash an Estate in your deck during the early game, you will most likely be better off trashing it. The choice of buying a card that Trashes an Estate rather than a Silver or other card will depend on the Kingdom cards available.
There are three main things you need to consider when trashing your starting cards:
- What will trashing do for me? If there's a great engine on the board, then trashing is a great way to help the engine components line up. On the other hand, if you're playing a money-based strategy, trashing is usually bad because your starting Coppers still contribute to your economy and there's a huge opportunity cost to trashing just your Estates (buying a trasher instead of a Silver, which slows your economy every time you draw the trasher, plus the decreased buying power on the turns you trash cards).
- How will the game end? If the game is going to end on piles, that means it's probably too fast to overcome a deficit from trashing your starting Estates. Plus, in alternate VP scenarios, Copper is a great card because it moves your average hand value closer to $5, so trashing your starting Coppers is an even worse idea than trashing your Estates. Conversely, if the game is going to end on Colonies, you have a lot more time to make up your initial VP deficit. The tempo of the game can also be affected by attacks, actions like Masquerade (you want to be able to pass your Estates to your opponent, which means not trashing them on your own), etc.
- How good is the trashing? Chapel and Remake are elite early game trashers. Trading Post is awesome if you open 5/2, but it drops to almost useless if you don't hit $5 until turn 5 or later. Upgrade is an awful card for just thinning your deck, but trashing your starting cards is an ok consolation prize while you're trying to set up Upgrade->Grand Market or something similar.
A couple of years ago at Prezcon, I won 4 (out of 4) games using a straight Bureaucrat - Mine strategy. I don't specifically remember if there was or wasn't a trashing action card available, but if there was, I didn't use it.
For what it's worth, there was a trashing action in the final, and I didn't use it, and I got trounced.
So "vital"? Not at all. "Valuable strategy"? Typically.