A quick look on GB shows anywhere from $20/1000 up around $50/1000 for cleaned and partially prepped brass. Good if you are looking to buy a batch but not so much if you are wanting to sell...
In general,,, 40 S&W is one of the cheaper brass buys out there. It's used a lot in LEO work, so their ranges get a lot. Add in the various handgun games where it's common & a lot can be had for very little. Are you wanting to sell or buy?
Hang tough-40's will come back, the 9 craz will soon be over, ballistics will win over, too many 9mm shootings with poor
results will change it or my name isn't John Jacob Dingleheimer Schmidt.