Buddy of mine does scrap commercially and I think he said that he gets just under $3.00/lb for mixed brass/copper. ($2.95/lb IIRC). Clean, pure ammo brass should be worth MORE! Sounds like you took your stuff to an aggregator. Somebody that buys small quantities cheaply, then resells large quantities to the smelters at a much higher price per pound. That's what most of the the roadside gold/silver/copper/aluminium buyers do.
If you don't have at least a barrel size load, no body is going to pay anywhere close to what the stuff's actually worth! And MOST of the local places just buy and resell and don't actually re-use the stuff so they're going to pay you the LEAST amount possible since the difference will be added profit for them. In short, get a good size load and take it to one of the real recyclers in Tampa or Jacksonville if you want to get a fair price!
Any reloadable brass is worth FAR more to reloaders than it is for scrap! And reloaders will buy small quantities!