I think it depends on what you're looking for, if it's a common snake it's easier to make a deal, some snakes are easy to make a deal on because they're uncommon as well. For example, I'm looking for a Desert Pied ball python, I'm certain there were more Albino Pieds or Clown Pieds produced this year than Desert Pieds but the Desert Pied would cost much less because it's "undesirable" and as a result easier to negotiate.

There's also an issue of people not wanting to advertise the price the snake will actually sell for, I'm seeing snakes selling often times for 25% or more under asking prices. I would start there, if they're asking $400, offer $300 cash and I'm betting they will say yes. For me economics would dictate taking that deal just due to the time, effort, and cost of keeping the animal for a potentially better offer in a market where the snakes aren't increasing in value. Clearly many of the people producing balls now aren't concerned with the economics of it but it should be a factor both give consideration to.

So my advice, don't make an emotional buy, know what the snake is worth going in and see what they can do.