Underlined Names signify the Primary Key for that table.

We want to know the list of Customers who have not purchased any expensive products (i.e., products whose average Price is 2000 or more.)

Write an SQL query that, for every such customer who has never purchased an expensive product, returns the CustomerId, FirstName and PhoneNumber. Return the results in the ascending order of CustomerId.

Consider the following database schema for a mobile phone store