(and) that ain't hay

informal And that's significant. Often used in reference to an amount of money. He got a $5,000 bonus this year, and that ain't hay. A: "It turns out that Erika's so-called 'fiancé' is still married to his ex-wife." B: "Well, that ain't hay! What the heck are they going to do?" They want to buy your invention off you for $250,000? Boy, that ain't hay! I hope you say yes!

and that ain't hay

AMERICAN, INFORMAL

People say and that ain't hay after an amount of money to emphasize that it is a large amount. For 13 out of the last 20 years Canadian bonds produced returns of more than 10%, and that ain't hay.