Definition of "cheap"

The sack that thou hast drunk me would have bought me lights as good cheap at the dearest chandler's in Europe.

c. 1597 (date written), William Shakespeare, “The First Part of Henry the Fourth, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene iii]

Where there are many sellers and few purchases, land will be cheap.

1691, [John Locke], Some Considerations of the Consequences of the Lowering of Interest, and Raising the Value of Money. […], London: […] Awnsham and John Churchill, […], published 1692

One saint's day in mid-term a certain newly appointed suffragan-bishop came to the school chapel, and there preached on “The Inner Life.” He at once secured attention by his informal method, and when presently the coughing of Jarvis […] interrupted the sermon, he altogether captivated his audience with a remark about cough lozenges being cheap and easily procurable.

1918, W[illiam] B[abington] Maxwell, chapter III, in The Mirror and the Lamp, Indianapolis, Ind.: The Bobbs-Merrill Company

[Rural solar plant] schemes are of little help to industry or other heavy users of electricity. Nor is solar power yet as cheap as the grid. For all that, the rapid arrival of electric light to Indian villages is long overdue. When the national grid suffers its next huge outage, as it did in July 2012 when hundreds of millions were left in the dark, look for specks of light in the villages.

2013 July 20, “Out of the gloom”, in The Economist, volume 408, number 8845

You grow cheap in every subject's eye.

1675, John Dryden, Aureng-zebe: A Tragedy. […], London: […] T[homas] N[ewcomb] for Henry Herringman, […], published 1676, (please specify the page number)

I need not request you to purchase them as cheap as possible

March 24 1658, John Milton, letter to Emeric Bigot