Hi great 5 shelf unit ready to go at just $40 bucks. 
It seems like a great shelf unit. If I were to come pick it up would you take $30 for it?
This shelf took some effort to put together since it's very solid. Can you give me a better offer?
I'm sorry, right now I'm in school and have limited funds. That's the best I can do.
How about 35 and I can help load it for you. Again it's already put together and you won't get a solid piece like that from a store already put together. 
Ok I can probably work with 35. Thanks.