I know the client states it needs something like 128 GB of space
Is that still the case if already having other elments of WoW already installed? i.e. classic wotlk, classic Era etc
is there any sort of overlap with the main data files? or is it completely seperate and requires the full 128GB of space (where i’d need to buy a new SSD…)
You don’t need to use 128Gb per version of the game. The first version of the game you install will use the 128gb, then any following versions you install will share those files and only need to download a couple or so GB.
Just ensure when you install additional versions you have the share game data option ticked. (It’s ticked by default anyway).
Wow for me uses around 90gb in total, but make sure you have at least 30gb( preferably more) of space free as much as possible. It’s “healthier” for your hard drive. Also as the person above said the different versions have files in common and they use them so let’s say once cataclysm comes you’ll have all cataclysm files from retail already and likely wouldn’t need to download too much