Should I be buying Alchemy Manuscripts?

[Deckard]

I'm not sure about most of you but I seemed to stumble upon a lot of manuscripts for Alchemy at the start of my playthrough primarily through exploring unexplored markers and generally opening every chest I could find. And I thought hey this is cool, this is rewarding me for my natural affinity to roam the wilderness in search of loot (a skill honed by Bioware and Final Fantasy games).

However, of late I don't seem to be finding many and I started to notice that the ones I was finding were generally enhanced or superior (sometimes for items I hadn't found the lower level). And then I noticed that some vendors were offering the manuscripts.

So my question is, if a vendor has a manuscript page do you think that means it's not out there in the wilderness somewhere? Or do you think there are just a few manuscripts that you have to buy and the others are there as a shortcut for you? Or should I start roaming Skellige because they're all out there?

Side question, has anyone worked out where you find some of the alchemy substances are they from manuscripts or bestiary updates?

[BDK]

I always buy the enhanced and superior stuff that I use and haven't found yet. Like superior grapeshot, superior thunderbolt, superior swallow etc. I'm sure it can be found somewhere but I can't really be arsed to go look for it.

[serker31]

Just buy everything you can. Better waste some money(which are plentiful anyway) than leave yourself without some important recipe.

[Warlord]

If you go to all of those treasure locations in the game you shouldn't. Otherwise, yes. Buying diagrams from merchants save you a lot of time.

[McCloud]

If you find a recipe out in the wild (a chest) the merchant(s) will no longer show that recipe though I don't think all recipes can be found by exploring and some still need to be bought.

Here's everying I found through exploring White Orchard

Albedo
Forktail Decoction
Katakan Decoction
Foglet Decoction
Noonwraith Decoction
Earth Elemental Decoction
Archgriffin Decoction
Dancing Star
Ancient leshen Decoction
Vermilion
Nigredo
Serpentine Silver Sword
Basilisk Decoction
Blunt Crossbow Bolt
Temarian poniard
Gven'nel
Broadhead Bolt
Cidarian gambeson
Dorian Sword
Serpentine Steel Sword
Exploding Bolt
Split Bolt

Yet the merchants still have a ton of recipes [in white orchard].