Full lightning protection makes no sense on a < 500€ setup. It's just not worth it.
However, it might be a good idea to ground the antenna, so that if it get hit by lightning, it won't damage your roof. Even better, set up a lightning rod.
(not that lightning rods don't really 'attract' lightning from a very long distance, so essentially if it gets hit, it means your structure was going to get hit anyway - you're just doing damage control)