From my experience in RPGs, there is seldom a balance in quality between items looted, bought or crafted. Most often it's just better to save your gold and equipt whatever drops from battle and then perhaps buy the occasional powerful item from some merchant. Crafted items is the category that most often falls short - it simply isn't worth the time or money to do it.
I've just left Hinterlands and have run across several merchants that sell schematics. I actually like the crafting system in DA:I and I wonder if it's worth it to buy them and craft items. From what I've seen on other forums, there are mixed opinions as to how good crafted items are.
TL;DR - should I skip buying schematics all together and just equipt whatever I find?