I think the Potion cost cards are too good too ignore, but I'm not positive.
I would open Masquerade + Potion on a 3/4 or 4/3. On 5/2, I'd open Travelling Fair for topdecked Masquerade + Potion. On 2/5, I'd be sad, and probably open with nothing + top-decked Masquerade. I'd intend to get a grand total of two Masquerades. Other sub-$5 non-Potion hands should be Mill or nothing - Silver shouldn't be necessary. With my Potion buys, I think I'd start with one Apothecary and then switch to Familiar if I could buy it and there was a decent chance it would hand out another Curse; I'd grab Apothecaries otherwise. It should be common to use Travelling Fair to topdeck the purchased Potion-cost card. On non-Potion $5+ hands, I'd start with a couple Royal Carriages for action splitting, then I'd pick up a Haggler. With Potion hands, I'd switch to buying $5s after 2-3 Apothecaries. With Haggler, I'd plan to pick up Gold + Royal Carriage, then Province + Expand, and then look to buy Province + Gold and Expand Gold -> Province each turn. It's possible to build more, with Artificer/Mill + Tunnel, and Ranger, but I think the faster Province grab I described would win.
If you did want to avoid Potion (which isn't crazy), I'd open Masquerade + Mill, grabbing a second Masquerade and additional Mills on sub-$5 buys. I'd get a couple Royal Carriages and a Haggler, just like above. But then, I'd pick up Royal Carriage + Ranger a couple times for additional draw. Then transition to the Province + Expand + Gold thing. In the best case scenario, it's faster than playing with Potion, but I think it'll be a challenge to play all the terminal draw reliably with so few cantrips (just Mill).