X is the suggested retail price of a particular car and y is price paid by a random car buyer. Is this a function?

No it is not a function

Step-by-step explanation:

A function is a relation for which each value from the set the first components of the ordered pairs is associated with exactly one value from the set of second components of the ordered pair.

Here in our question first component is price of a particular car

second component is price paid by a random car buyer

now

(price of a particular car) can be same for 2 or more (price paid by a random car buyer)

Hence

(first components) can be same for 2 or more (second component)

hence

(first components) is not associated with exactly one value from the set of (second components)

Hence it is not a function