Hi can you tell me a little about the bike you are selling?
It's a vintage, one of a kind. We actually had it assembled by hand with performance parts, it's definitely a special bike for enthusiats. 
My son would love this bike! Are you willing to come down on the price at all?
I'm willing to negotiate, but I don't have too much wiggle room on it.
I would like to offer $300, how do you feel about that?
Can you meet me halfway on the price? $330 and I'll even throw in the spare tire I have for it.
At the price of $330 could you drop it off at my house for me?
Sure, as long as you're local.