cheap / chēp/ • adj. (of an item for sale) low in price; worth more than its cost. ∎  charging low prices: a cheap restaurant. ∎  (of prices or other charges) low: my rent was pretty cheap. ∎  inexpensive because of inferior quality: cheap, shoddy goods. ∎ inf. miserly; stingy. ∎  of little worth because achieved in a discreditable way requiring little effort: her moment of cheap triumph. ∎  deserving of contempt: a cheap trick.• adv. at or for a low price: a house that was going cheap .PHRASES: dirt cheap very cheap or cheaply: the auctioneers let us have it dirt cheap.on the cheap inf. at a low cost.DERIVATIVES: cheap·ish adj.cheap·ly adv.cheap·ness n.

cheap adj. and adv. XVI. ellipt. for †(at) good cheape (XIV) ‘as a great or good bargain’, phr. formed, after (O)F, à bon marché ‘at good market’, on ME. chēp, OE. ċēap bargain, price = OS. kōp, OHG. kouf (G. kauf) :- WGmc. *kaupa m. (cf. ON. kaup n.); based on an early Gmc. adoption of L. caupō small trader, innkeeper.

cheap cheap and cheerful simple and inexpensive (late 20th century, perhaps in specific contrast with the early 19th century cheap and nasty, which linked low price with bad quality).
it is as cheap sitting as standing extra comfort will not necessarily cost more; this saying recorded from the mid 17th century, is often used literally.