First per Smiles comment. I work in building maintenance and the money, aka credits I earn there I take to a shooting range to buy and learn to fire a weapon. So I learned firearms from doing maintenance work. Pig farmers send their children to college off of money earned from pig farming to become computer programers. So the purchasing of skills I don't see as unrealistic. Some people like grinding and will probably buy up their axe skill with credits earned from kill critters with their axe nothing wrong with that, but a game creator in my thoughts needs to look past just the hack and slash players because there is a whole other group of players that after they master all the trades of a game and complete all the quests they move on to the next game. Why? because there is no reason to stay.
Next fireside I could not agree more with you all you saw so far was my CGC section of my ideas. Now lets talks about the actual game world. I hate static worlds and lets face it thats what everyone has made to date. All the crafting materials spawn in the same place. The towns never change until the game creators do some huge event. The quests are always the same. Hell in WoW I got to the point where I did not even have to read all I did was run my same old circuit of quests and could blindly level a character to 40 in a weekend. Thats not gaming thats just doing boring math problems all weekend.
How do you break free of having a static world? Make the Player Characters the NPCs. How do you make the Players give other Players quests? Create Needs. How do you create needs? The players actually build the meat of the world. My version of a none static world has only the base land masses, mountains, rivers, oceans, deserts, grasslands, tundras. There is one town to start whole world. In that town are people who only sell seeds, tools, and simple weapons. The rest are made only by players. In this game the skills make the person define who they are and what they want to do in the game.
Leadership - Someone with the leadership skills gives a party buffs on the low end of skills but on the upper end they can become mayors, generals, lords, kings. They can actually enter a section of the game where they can set tax rates for their town, castle, feifdom, kingdom. Of which they can earn credits. But to make those first steps to work up to becoming a king they need, carpenters, masons, heralds, scribes, so on and so forth.
Weapons Smith - can make all sorts of weapons to infinity bonuses howerver they need engineers to build a mine, miners to mine the ore, carpenters and masons to build their buildings
Fletchers - can make bows and arrows however they need farmers to plant trees, harvesters to harvest lumber, engineers to make lathes, hunters to kill feathered creatures.
So on and so forth.
So whole forests can rise up over night in areas as well as whole towns just from the players building things. They can also be destroyed over night through wars between neighboring kingdoms.
You have to think beyond the hack and slash battle and into a completely knew virtual reality. Players will not only have an effect on a game world like this they will control it.
I know what some people will be thinking too. What if a single player starts getting too powerful? Well just as there is old age and death in the real world there is old age and death in the game.
I know there are programers out their cringing at trying to figure out the strings of codes for doing this but honestly its not all that involved. There does not have to be huge differences in all the trees in the world for example there can be just a few visuals and the values of the trees would come from the skills of the farmer, and harvester. A begining farmer and harvester might be getting lumber X1 where someone who has done it for a few years are getting lumber x10. This lumber depending on the skill of the carpenter might be making a staff x1 or a staff x10 and if x10 lumber is turned into staff by a x10 carpenter you have a x100 staff.... everything hinges on the other things.
There will always be player to player involvement thus there will be limited need for quests to gain skills. Because by your trade what ever those trades are you will gain credits. With no need to do quests GM's will no longer have to listen to the crap of "Blah quest is broken again" "I did not get the X15 leather drop from the boss like I was supposed to" So GM's will be free to do real things that improve game play like host special events. Design and Run special dungeons. You know like the good old days in table top when the GMs would actually challenge players rather than just play mommy and wipe their noses.
Oh and did I mention with simplified worlds you also have the possibility of Space games where you actually have multiple worlds to explore and do business with rather than being stuck in one.
Of course there are powers as well. Lycanthrope, Vampirism, Telekinisis, Magic, blah, blah, blah. These naturally run more expensive than standard skills
Also remember that the skills are based off of a 16 attribute system so it becomes necessary to work toward raising attributes.
Another skill I toyed with in my mind was Wealth for those who dont get as much time to play as others so that they could accrue credits daily even when they were not in game. For us old working folk that pour 36 hours of game time into a weekend and then dont play through the week.
Thats the guts and gile of it. Feel free to ask me specifics of how to handle anything in particular I have most likely put thought into it.