Green’s Dictionary of Slang

a go, each; usu. in comb. with a sum of money, e.g. 10 pence a throw.

1896		Ade Artie (1963) 63: There’s some o’ them guys out in our ward can’t make out how it is that Jimmy can afford to buy wine at four bucks a throw when he’s only gettin’ three a week.
1901		‘Hugh McHugh’ John Henry 9: A New York theatre where you can roll around in an orchestra chair at fifty cents a throw.
1913		D. Runyon ‘In Old Juarez’ 1 Jan. [synd. col.] Where chili is fifteen cents a throw.
1927		W. Edge Main Stem 17: De flophouse is free and de chuck is tirty cents a throw.
1935		W. Smith Bessie Cotter 9: Ten guys a night, even at five bucks a throw, are no good.
1947		B. Schulberg Harder They Fall (1971) 73: Know what Superman sells? Eight, ten million copies. At a dime a throw not bad.
1954		Wodehouse Jeeves and the Feudal Spirit 25: He will squander a fortune [...] at twenty-five cents a throw.
1963		M. Braly Shake Him Till He Rattles (1964) 100: He knew one thing sure – people weren’t in here to pay a dollar a throw for Dino’s warm ginger ale and cold coffee.
1976		N. Thornburg Cutter and Bone (2001) 109: The very best call girls [...] Hundred to hundred-fifty a throw.
1981		A. Payne ‘You Need Hands’ in Minder [TV script] 24: They’ve got Cheval Blanc ’73 for eighteen quid a throw.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 141: [H]e took to dispensing, at a reasonable hit per middy (tuppence a throw), his own excellent ale .
1999		Indep. Mag. 23 Oct. 43: £1 a throw.
2003		McGill Reed Dict. of N.Z. Sl. 211: throw The value of something, used in conjunctive phrases such as ‘ten cents a throw’, from the cost of a sideshow turn. From mid 1950s.