I feel like making some comments about all the possibly relevant cards (meaning: realistically possible to get or just hilariously bad or otherwise interesting) in this variant right now, so I'm going to do it!
Alchemist - Essentially a $1 Lab, which is good but not great, remembering that it'll just draw Coppers and Estates most of the time.
Apothecary - A power card. Getting them is very easy and just a couple of them will allow for relatively expensive purchases, if there any expensive cards you want.
Apprentice - Another power card, a must get. Absolutely sick with Shelters.
Familiar - You want it if you can get it. Emptying the Curse pile in the opponent's deck instead of your own is a big improvement for Duchy rush.
Golem - Depending on the kingdom, it might be anything between absurdly broken and absolutely useless. Usually quite close to the latter. Even if you only count games where it can be bought.
Adventurer - A solid card, you should usually get one or more.
Bureaucrat - The most powerful card in all of Dominion. Well, not quite, but it's actually very powerful and one of the top cards.
Cellar - It's not a bad card, but it's not very good either. You might prefer a single Cellar over a Copper, sometimes two, but probably you should be focusing on the Coppers.
Chancellor - You probably want Chancellors, it's a decent card.
Chapel - Should be ignored on most boards.
Council Room - Very powerful. It can enable alternative strategies in theory but probably doesn't in practice, since it's so good in Duchy rushes too.
Feast - Is useless in a very entertaining way.
Festival - You probably don't need this that much.
Gardens - A Gardens based strategy isn't viable, but a couple of Gardenses in a Duchy rush can be helpful if you can get them.
Fairgrounds - I imagine that in the right circumstances, this can even beat Duchy rush. Maybe. It's our only hope!
Farming Village - If Farming Village is the Village you need, you are better off choosing a way to rush the Duchies without the need for a village.
Fortune Teller - It's not going to make a big enough difference to be worth it when you could just be gaining Duchies or Estates instead.
Altar - Great for piledriving purposes but otherwise useless.
Armory - Same as above, except it's better.
Band of Misfits - There is little point in getting this instead of the $1 you want to play.
Bandit Camp - Very good.
Beggar - Very good.
Catacombs - Very good.
Count - Awesome.
Counterfeit - It's strictly better than Copper.
Cultist - I think Cultist is a great card here, because it helps you, hurts your opponent and empties a pile.
Death Cart - A convenient way of getting those expensive cards you want.
Feodum - Without a way to get tons of Silver, this isn't very good.
Rats - This with Apprentice = awesomeness. It's pretty difficult to get Rats, though.
Border Village - The cheapest village in the game; it's not game breaking but decent.
Cache - It's very good.
Cartographer - Probably quite good.
Crossroads - Decent, but not great.
Develop - Develop Estates into Duchies (and sometimes something starting with an F) sounds like a good plan to me.
Duchess - You don't want to ever buy this card because Duchy costs $4 too and then you'll get one of these for free.
Embassy - The Silver gain is much more relevant than normally. The card is still good, but less so than in regular Dominion.
Trader - Yo dawg, I heard you like piles so we put a Silver pile in your discard pile.
Baron - A great card, first you can get some $ to buy some Duchies, then you can start gaining Estates.
Bridge - it's good, but not totally awesome.
Conspirator - I'm not sure if you want a terminal Silver for $3. You probably do if there are no other terminals you want.
Coppersmith - Should be quite good.
Courtyard - It's a good card, loses a lot of power because of Silver not being available, though.
Duke - The most powerful card.
Swindler - Can still replace Copper with Curse, but now it can replace a Swindler with a Scout, too, so you don't have to spend time thinking if you want to give your opponent a new Swindler or a Silver instead. Unless you want to.
Black Market - If it wasn't swingy enough for you in normal Dominion... that aside, it's a terminal Silver for $2 which should be decent in any case.
Envoy - You have to pass up a Duchy for it, which isn't necessarily a very good idea, considering that it'll just draw mostly green cards in the late game.
Bank - Very good.
Bishop - Bishop could beat Duchy rush.
City - Another cheap Village. It's almost guaranteed to level up at some point.
Contraband - Having Duchy named hurts a lot, you don't probably want it.
Counting House - It's a good card.
Expand - Very good, you can replace your Coppers with Duchies.
Forge - It might take quite a while to make decisions. It's not very good on most boards, I imagine.
Goons - It's still very powerful. The discard attack loses a lot of power, but the VP part is now so strong that a single Goons alone can turn the tides. Not being able to buy free stuff is a big drawback though.
Grand Market - The most expensive card in this variant.
Peddler - Have you ever felt like it is a waste of something when you have 5 actions in play and buy Peddler? No problem!
Ambassador - You could buy it and a Curse, but it's difficult to say how good it is.
Bazaar - Another cheap Village and a very good one at that.
Caravan - It's a good card, though +card is still less useful than normally.
Cutpurse - Very good.
Embargo - Win the Duchy split and Embargo the Estates.
Explorer - Man, they can't all be the best $5. Actually Explorer is quite good here.
Ghost Ship - Painful games.
