Question: I've been looking at [the cards from Dominion: Alchemy](http://dominion.diehrstraits.com/?set=Alchemy) and want to use some of them in my own games through proxying of the blank cards. However, I don't feel like delving into the whole potion thing, especially since it would be annoying to have to proxy at least 4 different cards (the potion and 3 kingdom cards to get the recommended amount of 3-5). So I figured I'd just give them costs in $ only and not potions. Another application of this might be playing with the alchemy cards if for some reason you didn't want to use potion as well. 

However, I'm not exactly sure what costs to use. A potion is roughly equivalent to a silver, but that seems like an oversimplification. One of the interesting things about alchemy is that you have to [buy the potions in order to access these cards and balance them with your other currency.](https://boardgames.stackexchange.com/questions/3116/how-does-the-addition-of-the-potion-treasure-from-dominion-alchemy-change-the-ga) This scarcity makes me lean more toward counting a potion to add +3$ to the cost. 

Does this seem about right? If not, could someone perhaps provide a case by case basis for the 9 cards this would pertain to (since Alchemist in a potion-less game would be rather odd I'm not planning on including it)?

Answer: 
One of the defining characteristics of Potions in Alchemy is that they force a reshuffle-delay. That is, you have to first invest in the potion, then reshuffle and draw it before you're able to spend it on a card. 

This is never going to be true of a cost that is just boosted to cost more coins, unfortunately.

I don't have any particular evidence to back this up but +$3 seems high, at least for some cards. Possession might warrant a $9 cost, I'm not sure, but some of the other weaker cards really don't feel like they'd work at +$3 to me. I'll try to come up with my per-card opinions at some point.

Bummer about Alchemist, too - it's one of my favorite cards from Alchemy. Then again, I'm a fan of big honkin' action chains.
Honestly, I would just proxy a pair of potions. Potions are different from normal treasures in that each player often will only buy 1, whereas a typical game will have multiple purchases of Gold and Silver by each person. So, making the Potion proxies does not require as many cards as Kingdom card proxies.

If your goal is to just play through the cards to see what it's like, why not take a stack of Kingdom cards that aren't being used in a particular game and pretend those are Potions for the game? I would recommend having a reminder in large letters for everyone to see so they don't accidentally play their "Bureaucrat" as a Action rather than as the Potion it's representing, but that would be a simple way to try out some Alchemy cards.