Keep an eye on the online shooting forums. 9 and 40 are so common you can sometimes score big. I got a USPS Medium Flat rate box (MFRB) full to bulging of 40 S&W brass from a person who sold it at scrap brass cost ($1/pound plus MFRB shipping cost). Some of these guys sweep up LEO ranges so their profit is 100% no matter what they get for the brass.