I don't know how this would work practically but I have been reading the forums and the main thing to me (and this is only my opinion) is:-
There is no real point.
No point in mining just to sell to vendor and no point in selling in auction cause someone else has the skill so they can go do it for themselves.
Everyone can do ALL skills so we don't really need anything from anybody. Unless, like me you've been in a position to not want to wait feeding batterflies for poop and bought a dozen from auction but even then, when the price goes up I get my glitchy butt down the mines.
I need to think about this more in depth but I have a few ideas that I would like to put forward and have a positive feedback from others. I understand that anything I come up with will be liable to be 'shot down' as a negative idea and that's OK cause I don't think I have all the answers but I would like to throw some of them out there. What if, and I hate this idea myself, the vendors did not buy from us. Then I would be forced to use the Auction which at the moment I don't bother with. What if only one full skill could be learned per glitch and although we know them all we would have to rotate between them (not sure how this would work). Piggies do not feed us meat that we can eat but only cook with so people down the mines would have to buy food. I am still thinking about a lovely glitchen who had learned crafting skill but I had already all the stuff I needed so did not buy anything from her but upon reflection would have had to if a) I did not have the skill myself and b) could not buy from vendor. See there are flaws here but by putting this down perhaps it can be built on and better ideas grow from these imperfect seeds.