While he doesn't give you much to go on, I do not see a serious downside at $480. I assume the buttplate matching means the stock probably does, that is sort of important to any value. I would say the stock has been tampered with, even beyond the interwar rework, better pictures would be helpful here. But, almost any property marked 98a will have seen a rework or two, which is where the takedown was probably added (assuming the stock matches the rifle)
Bottom line is the parts are probably worth around $400, maybe more if they are not refinished and the bolt is not altered, and the probability is that you will at least break even on a resale. The wrist problem if repaired properly is not a big problem, but again he doesn't go overboard reassuring potential buyers.
*** whether this is the best use of $480 is another question though, - I would probably pass and wait for a better rifle, keep your $500 safe and try to add a little to it and get a really nice bolt mismatcher. It wasn't long ago that you could find a nice matching 98a for around $600-700, my bet is you can still come across one with some "character" for around that range if you have patience and ready cash.
