Hello Tahru... I like to keep my things organized (Quest related) instead of having all these items together, etc. -Alice
There is no NPC but many player vendors sell them for between 100-200g. Maybe eben the public merchant. If you still got that problem tomorrow (GMT+2 here, it's midnight, need to go to bed) shoot me a friend request, in game name is Lilian Federkiel, I'll set you up with some.
I hope Tahru meant that as a joke. Bags currently don't work very well and the whole inventory system seems designed to eliminate their use by working like a searchable database :/ But I've been asking for what you want for a long time... a Provisioner NPC that sells bags, torches, lockpicks, etc like we saw in the old Ultima games. No such luck as of yet. It seems that the game is of the mindset that bags are vanity items.
Welcome @Alice Liddell! Currently "small bags" do work when used in your inventory. They act like sub directories in a file system, and can hide stuff you don't want to have cluttering up your interface. If you are able to craft one at a tailoring station, the recipe is 2 leather + 1 coil rope + 1 tailor scissors. Rope can be found in mines, and leather can be made at a tanning station using 2 animal hides + 1 curing salt + 1 tanning knife. They are also available at vendors, or if you whisper me in game I'll make one for you for free. I hope that helps.
Do backpacks function the same way as bags? They don't actually give you more storage, just a way to organize things?
At the moment that is how it works, as mentioned we want a lot more from those bags. I want to be able to put a whole outfit in one and sell it. (like for example: shoes, gloves, hat, dress). Like in UO and label the bag and set the bag on a table as well if I want. We can keep mentioning and it could be on the 'to do' list already, let's hope. @Lord British2, @DarkStarr.