you just told him getting new ram would be unneccecairy (wich i agree with) and now you tell him to get new ram?
the difference between pc5300 and pc6400 really isnt big, when you take it all together, even with seling your ram (while getting a good price for it) and buying new ram, I dont think it'll be worth the 'wasted' money. sure, if your ram is damaged, why not spend a bit more money on pc6400, but personally I'd wait till the system is getting too slow and you're going to replace quite a bit anyway
(btw, the pc looks nice balanced, gj there)