You can’t buy this if you have any Coppers in play.
Grand Market is an Action card from Prosperity. It is the ultimate Peddler variant, giving an extra and a +Buy, making it quite powerful if you can get it. Since it cannot be bought with Copper, it can be difficult to get early in the game; but the card creates somewhat of a snowball effect, in that Grand Markets themselves are a very efficient source of non-Copper money, so having Grand Markets makes it even easier to get more Grand Markets.
 Official FAQ
- A single Copper in play is enough to stop you from buying Grand Market.
- You do not have to play all of the Treasures in your hand.
- Coppers in your hand do not stop you from buying Grand Market - only Coppers in play do.
- Coppers that were in play earlier in the turn but aren't anymore also do not stop you; if you have 11 Coppers in play and 2 Buys, you could buy a Mint, trash all of your played Treasures, and then buy a Grand Market.
- You can gain Grand Market other ways - for example with Expand - whether or not you have Coppers in play.
- Treasures other than Copper do not prevent you from buying Grand Market, even if they are worth Loan). (such as
- Remember you cannot play more Treasures after buying a card.
 Other Rules clarifications
 Strategy Article
Original article by theory
Grand Markets are almost always preferable to Golds, except when playing terminal card draw+Big Money. So long as the average card value in your deck is greater than , the self-replacing, non-terminal Grand Market is monetarily superior. The +Buy is always nice, and unlike Golds, Grand Markets are affected by Throne Room and King's Court.
Unfortunately, it’s difficult to buy Grand Market, since only quite strong decks are able to producewithout relying on Copper. There’s several ways to do so before your deck gets to that point.
The first, and most obvious, way is with Actions that give money. Unfortunately, it’s difficult to get enough of them together; it normally takes quite a while to draw 3 Festivals in one hand. Grand Markets themselves are great for grabbing more Grand Markets, though.
A better way is with Secret Chamber, Storeroom, or Vault, because it basically lets you use Coppers without having to play them. Of course, Vault is best for this purpose: because it gives +2 Cards, it guarantees at least . In this game, by going Vault/Chapel instead of Torturer/Chapel, I get my Grand Markets out much sooner than he does.
Quarry also helps; it lets you buy the Grand Market when paired with either two Silvers, a Gold, or another Quarry. (If you use Black Market to play the Quarry during your Action phase, you can use Ironworks/Armory/Workshop to gain it as well.) And the Copper restriction on Grand Markets doesn’t apply when you gain the card with Remodel/Expand/Upgrade.
Of course, if you trash your Coppers, buying Grand Markets isn’t a problem. Nor is it a problem if you have a ton of Silvers in your deck, either from Bureaucrat or Jack of all Trades or Trading Post, but having so many Silvers can be a liability, a sign that you’re not ramping up your deck quickly enough.
In all other respects, Grand Markets have the pretty much the same advantages and disadvantages as Peddlers and Markets (though of course beefed up considerably): they are most valuable in dense decks with high average card value, and are vulnerable to small handsizes.
- Secret Chamber/Vault
- Moneylender/Loan/Spice Merchant
- Silver-gaining cards like Bureaucrat or Jack of all Trades
- Actions that give +Conspirator) (especially
- Trashing cards (both to clear Coppers and for a denser deck)
- Coppersmith/Counting House/Apothecary
- Attack-heavy opponents in general
- Bank, because it depends on large numbers of Treasures, typically Coppers
 Alternate versions
 In other languages
- Czech: Velký trh
- Dutch: Grote markt
- Finnish: Suurtori
- French: Grand marché
- German: Grosser Markt
- Italian: Mercato di Lusso (lit. luxury market)
- Japanese: 大市場 (pron. dai ichiba)
- Polish: Wielki targ
- Russian: Центральный Рынок (pron. tsyentral'ny rynok, lit. central market)
- Spanish: Gran Mercado
 Secret Historyand was "+1 Card +1 Action + ." People sure complained about it not having +1 Buy. "How is it a Grand Market?" they'd say. So I added +1 Buy, and then later took the anti-Copper clause from another card.