Respawning on shops

[chapapote]

Hello! I'm new here!
I've noticed that, if you check what a merchant has to sell, complete some missions and then go back, the merchant has new stuff to sell. I've sometimes noticed that, when selling some stuff not included in the merchan's normal stuff, after going back the merchant has replicated it and generated lots of it just as it was part of his normal stuff.
My questions are:
-Is this normal or can only happen by dumb luck?
-What objects can be "replicated" using this method?
-Is there a limit for the amount of objects the merchant can sell?
-What's the requiste for the merchant to sell new stuff (complete a concrete number of missions...)?
Thanks in advance.

[Guest]

Hi.
1) It's normal.
2) Prototypes (for everything) and runes. Materials can't be replicated.
3) The only limit is the amount of objects the merchant is selling at the moment.
4) Each completed quest the store is replenished.

[chapapote]

OK, thanks!