This mod can be purchased unranked from the Void Trader Baro Ki'Teer for 220,000 Credits 220,000 and 300 Ducats 300. Note however that Baro Ki'Teer's stock changes with each appearance, and may not have this item available every time.
Primed Reach is essentially the Reach mod with Legendary rarity and 7 more ranks. It is considered the same mod as its Common counterpart, and thus both mods cannot be equipped together.
As with its normal version, Primed Reach extends the normal attack range of Thrown weapons (e.g. Glaive), but not their throwing attack range.
Primed Reach is the first Primed mod whose base mod had a maximum rank of 3, rather than 5 as with other Primed mods.
It is also the first Primed mod that more than doubles the original mod's effect.
Reach / Primed Reach - Will now increase range in a way that has been normalized. In the previous incarnation, long-range weapons were getting too much of a benefit, while short-range weapons were barely seeing any increase at all.