Good afternoon!  Interested in the bike?
I would love the bike!
It's a good bike, but we don't need it anymore.  I have it listed for $40, but I could probably take $35. 
Hmm that sounds good, but is it new?
It's less than a year old, and in good shape. 
Not bad at all! Does it come with anything?
I'll throw in the training wheels. 
Great! 35 good?
Sounds good to me
Should I pick it up?
Yeah, that's fine. 
Great! Deal!