price buster
informal (originally US )
noun
1A retailer, business, etc., that substantially reduces (or occasionally: inflates) the price of an item or commodity; a person or measure effecting a large reduction (or occasionally: increase) in price.
2An item or commodity selling at a reduced (occasionally: increased or inflated) price (also in extended use).
Origin
Early 20th century; earliest use found in The New York Times.