Oh lol. gin stands for "Get It Now". The auctioneer can put a Gin price (Aside from the normal action min.) where someone can instantly "buy" the item for a large amount of credits. This is usually good for if you want a certain price on something and think the bidding might not get up to it. And if there's somebody who wants it badly enough to fulfill the Gin price. But.... you do need a certain number of badges to unlock the Get It Now option on your auctions. Also the minimum Gin is 2000, so that guy doesn't know what hes talking about.
Also if you can offer something high, can you accept bid and give it that person if you think it has gone high enough or do you have to wait? just asking
its always really fun looking back at the comments and seeing all those morons saying things like "ill give you 600 gin, ill give you 1000 gin." HAHAH its at 14000 right now.