select s.name from (
select f.id, f.friend_id, p1.Salary my_salary from friends f
inner join packages p1
on f.id = p1.id
) a
inner join 
(
select f.id, f.friend_id, p1.Salary friend_salary from friends f
inner join packages p1
on f.friend_id = p1.id
) b
on a.id = b.id
inner join students s
on s.id = a.id
where a.my_salary < b.friend_salary
order by b.friend_salary