Be really friendly and chat with him all he wants! Also, tell him you will take both as a package deal if you get the upper end of the discount range (20%).

That means
Total price ......... $550
20% discount ..... $110
Out the Door ...... $440

(Well, probably need to pay tax, but still ...)

If you can spare the money, you will not regret it.

__________________
You're shy a few manners.