I'm trying to understand the logic behind the vendors, as seen in the tutorial zone.
If there is no logic, then just say so. As I've mentioned earlier, much of Spiral Knights seems to be the "tried and pointless tropes" of MMO's made into a playable game.
But in the tutorial zone, we have vendors offering stuff that probably half of the people going through cannot afford by the first time they find the vendors. We have vendors that are apparently making a living in the hardest to reach places -- the bottom of dungeons. Where people aren't expected to return for later visits.
We have recipe vendors that won't tell you what the recipes require or cost to operate. There's no way to know if it will be obsolete by the time you can afford it, or if it requires a drop that you missed. Heck, it might require a drop from a monster that you haven't seen yet, that comes later in the dungeon -- but after finding and killing them, you didn't get it.
There's no indication of whether these items and recipes will be offered again later. No indication of how significant or valuable these will be. No indication of whether the intention is "replay this area multiple times" (shades of Everquest), or whether the intention is "Naah, you can skip it", and if you're expected to skip it, why is it there?
The vendors seem well-placed to me, they're in every town and one halfway between each town. "Dungeons" have "bottoms" only if their gate didn't receive enough minerals from players, otherwise they go through to the next town or The Core. You'll always be able to come back to all the towns.
Why are you so quick to complain about every little thing? It seems like you're not even trying to take the time to learn the ropes; this is all stuff I picked up in the first couple hours of gameplay.
If you don't cut down on your posting and figure out to not project such an air of complacency, people will be unable to empathize with you and will only bash you when you post.