He's only 13, so he doesn't have the video and audio files (and may never). I already have a 1tb external I use for backing up stuff, i guess I could let him use this or buy another one should he reach that point.
the reason i suggested it is also because the write/rewrite cycles will degrade an ssd much faster than a hdd, so documents etc. are better stored on a hdd than ssd.
SSDs (At least the Samsung EVOs I've bought) have an expected lifetime of around 10 years of average use. The rewrite cycles are far less likely to be a problem than the potential mechanical issues a platter drive has.
That said, make sure you turn OFF the defrag in Windows for an SSD. They don't require it, and it will only produce more read/write cycles.