That's a good price, if you need a hood, you can get one that screws into the front threads, or get it fixed by Canon.
It does seem likely thaty the lens has been dropped and might have decentered elements, which can also be fixed at Canon.
The one critical thing is the zoom. Loosen the zoom ring and verify that the lens zooms as smooth as glass. If it binds or is rough, the price to fix it will astound you, and it will soon lockup completely.