This is a good test of behavioral economics. You can buy this tennis estate for $8.8 million. Now $8.8 may strike some as expensive but the seller is offering a "lifetime supply of tennis balls" to the person who buys this home. I understand complementary goods and this is a nice case. Will the "free" balls tempt you to buy this house?
Now I must warn you that in the fine print it says that "lifetime supply" merely means 1000 cans of balls but still this is a nice test of our love of "free stuff".
This home is located about 4 miles from me --- so we would be neighbors but there are other "lovely" new homes closer by such as this one.