1)There is absolutely nothing wrong with it
2)I got it for $200
3)It's been worn only a few times.
Did you get it x-rayed???
I've dropped previous helmets before and they 'appear'to be fine. And I have continued to use them. However I would not buy a used helmet - period.
Also head lice cannot be removed with common cleansers!
It's your head though... good luck.