. The rules are simple. It's the salespersons job to get the most money he can and it's your job to pay the least you have to. I'm a maniac when it comes to buying a new car, motor home, house, etc.
I'd offer something low and let them counter. Ask a few more times and when he won't come down any more, start calling other places and ask them to beat the price.
Repeat as necessary.
You'll find out the bottom price soon enough.