select name
from    (select s1.name, p2.id, p2.salary 
        from students s1 join packages p2 on s1.id= p2.id
        order by p2.salary asc) as jo1n
    join
        (select f1.id, f1.friend_id, p1.salary
        from friends f1 join packages p1 on f1.friend_id= p1.id
        order by p1.salary asc) as jo2n
    on jo1n.id=jo2n.id
where   jo2n.salary > jo1n.salary
order by jo2n.salary;