Re: all this techy stuff is great
This article indicates why SSDs of this design are *unlikely* to drop in price dramatically, given how fiendishly difficult they are to manufacture.
As for 4K videos, those are a nice example of material which is optimally stored on HDD: large contiguous files accessed sequentially.
Of course, the ruggedness of an SSD is a benefit if this is a portable device being thrown around a lot. But I'd be inclined to use the SSD for current working set, and archive off to HDD when you get home. And back it up to a second HDD, preferably remote, if the data has any value to you.