The juice aint worth the squeeze

Does anyone know where the phrase "the juice aint worth the squeeze" originated. Ive seen it as "isn't" however, it is mostly used using the word 'aint'. I googled it and found many thousands of references, but nothing here in the Phrase Thesaurus. Anyone know???

Well, the first time I read it was in "Close Range: Wyoming Stories," a short story collection by Annie Proulx.