杀价 shājià
[offer to buy sth. cheap, knowing the seller needs cash;force down prices;sell at reduced price;slash prices] 买东西时压低价格
那 掺水掺假、抬价杀价的把戏,瞒不过他的眼睛
压低价钱。 《官场现形记．第五回》：「这可由我杀价，这叫个里外两赚。」