Streetail

The price of an item, often stolen or fenced, that would be bought on the black market or on the street.

That bike costs $400 retail but I can get you one for $250 streetail.

StReetail

Contraction of the words "Street" and "Retail". Typically used when referring to the "Street Retail" price/cost of an item that is often or only sold on the "streets", but is also generally available in bulk quantities to middle-men who pay a "wholesale" rate, and have "retail" or "streetail" prices that they sell the item(s) for.

LaNaShaQuancita: Hey how much were those weed-tampons you were getting?

Tyrone: Uh, they streetail for like $5, biznatch!