Burton On Trent
Sysop of "Big Bang Burger Bar" Forum (www.bigbangburgerbar.co.uk)
Organiser of "Raiders of the Game Cupboard" (www.raidersofthegamecupboard.co.uk)
From the rules page4:
Purchases ALL the Cargo in this Port, if his stack of coins
is the only one (remaining) there. The coins spent to acquire
this Cargo go into the common Pile of Money. The
(now-empty) warehouses in the Port are immediately refilled
with new Cargo tokens drawn from the bag. If the
bag runs empty, reshuffle all Cargo tokens discarded in
Phase 2 of prior turns back into the bag.
If the bag empties re-fill from the discards (emphasis mine).