The only thing I detest about negotiations is that (in GE at least . . . no clue about elsewhere) they can request special goods (promethium, orichalcum, etc.) but those special goods are never rewarded in GE chests or from GE relics. I simply won't use special goods in negotiations since they aren't overflowing for me yet, but beside that I never have any issues negotiating all four levels of GE weekly. It does require logic, paying attention, and strategy, depending upon how many possible goods are in the negotiation, but it is not that difficult.