A Lamborghini is a very expensive car and getting it as a birthday present would be considered a huge luxury, while a Mercedes is already a luxurious car and therefore getting it as a present would not make someone feel as affluent.
Consider the statement "I only got a mercedes for my birthday, but I thought my dad was gonna get me a lamborghini...". Based on this "I really wanted a Lamborghini as my birthday present, but now I feel very affluent for settling with a less expensive Mercedes car." a true statement? Yes, no, or I don't know?