We weren't really able to upgrade our Eureka gear until we could farm fragments in BA. I suspect there will be another way to get coins when the next relic patch shows up. It's not really realistic rightn not to try and upgrade one chest piece with 999 coins when you get a maximum of 26 per castrum run. At this point I would simply focus on buying the base gear with is pretty cheap when it comes to coins needed.
Oh that's interesting I wasn't aware of that.
