godan verb (-ku), transitive verb
beat down prices; haggle aggressively; strike a hard bargain
Used when a buyer aggressively negotiates a much lower price, often with a negative connotation of unfairness or taking advantage of the seller.
彼は市場で骨董品を買い叩くのがうまい。
He's good at beating down prices for antiques at the market.
あの客はいつも商品
That customer always tries to strike a hard bargain.