As you can see, the criteria was not that high and the prices did not vary too much.
1775. Price of SlavesSource: New York Gazette and Weekly Mercury, February 13, 1775 in Abram Wakeman (1914). Historyand reminiscences of lower Wall street and vicinity. New York: The Spice Mill publishing co., pp. 23-24.
TO BE SOLD.“At the office of William Tongue, Broker, at the house of the late Mr. Waldron near the Exchange (lowerend of Broad street), the following goods and merchandise, viz.:
“One Negro Wench, 22 years old, has had the smallpox, is a useful domestic Price 80£
One Negro Wench, 40 years old Price 50£
One ditto Wench, 30 years old Price 50£
One Negro Man, 27 years old, is a good farmer Price 90£
One Negro Man, 27 years old, is a tolerable cook and gardener, etc.Price 100£
One Negro Boy, 16 years old Price 90£
One Negro Wench, 30 years old, with or without her son 5 years oldPrice 60 or 80£
One fine Negro Wench, 22 years old, every way very useful Price 80£