Frankly the vendors apart from a certain mabari (who has the change, remember) and the skyhold merchants have very little that wouldn't theoretically be beaten by a lucky random drop. Or even most of the fixed ones...Vendor inventory and RNG drops are possibly the most frustrating parts of the game IMO. Trying to get the best Tier-3 armor waswa bitch.That was the only easy part, I think the loyal mabari is guaranteed to carry the top model for your inquisitor's class. That's what I got, and I've read most others getting too.
Now, getting a 2h sword that is not ugly... And there is no decent 1h sword in the game at all, Caliban at least looks nice but, well, is nit very good.
Either by design or by necessity, they're going to have to implement a less random top tier schematic vendor in dlc.