I'd open Potion/Shanty town here.
Turn 3/4 gets me scrying pool and on $2/3/4/5 I'd get CM/CM/Ironworks/Upgrade.
I'd hope that's the last CM I buy for a while, from here on I'd prefer scheme.
I don't think opening Irownworks/CM has enough chance to hit $5 to justify delaying the potion here, and even if you hit it I'm not sure you're ahead.
Also I think Scrying Pools are important almost immediately, and this game will be really short if both players build the engine.
Ironworks for Ironworks, draw it and repeat means that pile is virtually gone as soon as the decks get clean, schemes will be out in no time and a 3rd one could be any of scrying pool, shanty town, candlestick maker.