The solenoid is sealed and "not serviceable" in this gen Corolla and checking the brushes is also necessary given the time that has passed. Chances are the brushes are basically worn out gone and would require replacement along with the solenoid. Starter failures are sudden and not in advance, so if the mechanic does not have the brush assembly and solenoid on hand, the mech can't do this slower and more involved work(for no difference in pay if he's flat rate) until the parts arrive.Most likely it was just worn solenoid contacts. R&R the contacts and possibly the plunger for less than $30.00, and it would have been good to go.
It is clear to me that the OP is not a wrench turner.