We live in a society where an animal is only worth what someone will pay for it. Often times vendors lose 3% to Credit Card companies off the top, so if you're paying in cash, getting a small discount helps both sides. Then there is also the side that says that if you pay in cash, they may not always report that to the Government for taxes, so they're not paying nearly as much in taxes. It's not necessarily honest or legal, but it's one of the loopholes in the current US tax system.
I will disagree with everyone saying it's best to wait till the end to do this. You do this when you find an animal you want. IF you know what the animal you want costs inside a range low to high, just make sure you walk in with enough hundred dollar bills in your pocket. Find the animal, look at it, talk to the breeder. Make sure you want it. Then pull out your wad and ask them: "What's your cash right now price?" - Chances are that if it's not a rare or difficult animal that you're going to get a decent discount.
I saved $150 on my pair of Clown het Orange Ghost M/F this way at Tinley and $50 on the Fire het Clown female I bought.
Paul