Revised my solution, making it a bit faster (and also conforms to supply rules!). Hopefully no big mistakes this time.
Supply: Bridge, Highway, Ironworks, King's Court, Nobles, Outpost, Throne Room, University, Watchtower, Wharf
Turn 1:
KC a University. Gain Ironworks, Throne Room, Watchtower.
Turn 2:
Draw King's Court, University, Ironworks, Throne Room, Watchtower.
TR a KC...
- a University (gaining 2x Highway and a Wharf).
- an Ironworks (gaining 3x Ironworks).
Play Watchtower (drawing 3x Ironworks, 2x Highway, and a Wharf).
Play Highway (drawing nothing), reducing costs by $1.
Play Ironworks (gaining a Wharf).
Play Ironworks (gaining a Wharf).
Play Wharf (drawing 2x Wharf).
Play Ironworks (gaining an Outpost).
Play Highway (drawing an Outpost), reducing costs by $2.
Play Wharf (drawing nothing).
Play Wharf (drawing nothing).
Play Outpost.
Turn 2 (Outpost, +6 cards and +3 buys from 3x Wharf - 4 buys):
Draw King's Court, University, 4x Ironworks, Throne Room, Watchtower, Highway.
*** Note that even though there's still 1 Highway left in the deck, it's impossible to not be able to draw the entire deck.
Play Highway (drawing a Highway), reducing costs by $1.
Play Highway (drawing nothing), reducing costs by $2.
TR a KC...
- an Ironworks (gaining 3x Nobles (revealing Watchtower and drawing 3x Nobles)).
- a University (gaining 2x King's Court and a Highway).
Play Nobles (drawing 2x King's Court and a Highway).
Play Highway (drawing nothing), reducing costs by $3.
KC a KC...
- an Ironworks (gaining 3x King's Court)
- an Ironworks (gaining 3x Bridge)
- an Ironworks (gaining 2x Bridge and a Nobles (revealing Watchtower and drawing Nobles)).
Play Nobles (drawing a Nobles and 2x Bridge).
Play Nobles (drawing 3x King's Court).
Play Nobles (drawing 3x Bridge).
KC a KC...
- a Bridge, reducing costs by $6. 7 buys.
- a Bridge, reducing costs by $9. 10 buys.
- a KC...
-- a Bridge, reducing costs by $12. 13 buys.
-- a Bridge, reducing costs by $15. 16 buys.
-- a Bridge, reducing costs by $18. 19 buys.
And I didn't empty out any supply piles, so you can probably extend this to get more Victory cards, or something.