It's meant to take some bit of currency to afford a non-Tabula unique 6L, unless you're going super hard on farming this past week or got super lucky, you shouldn't be able to have one by now. What I do is save up about 300 fusings, and link until I hit less than 150 fusings, and then stop at the next 5L to repeat again later. Presumably you could sell the fusings and buy a 6L outright, but they're usually overpriced compared to linking it yourself. If I still don't have one by the time the rest of my gear is set up, I'd then look at buying one, but that hasn't happened yet.