I am completely bias of course.. but for my two chyens worth i like it.. with caveats.
Apologies in advance for going off on a bit of a tangent..
First off ive always thought that more love is needed for Trader characters, ive written plenty of posts and bored jinx to tears probably with my endless notes on the economy and what not.. so yay for some market love.
Ive always thought that the markets should be more dynamic and the more a person invests in Trade (and even mixmash) the more they should really benefit from working the markets. Not just in prices but being able to find items that those that havent invested in trade and therefore their market connections shouldnt.
Ive also been thinking that since the mix has more than one market, it would be cool if they because a resource as such that the gangs should fight over, waging not just turf war for the sake of it.. but economic war by making each others market less desireable to be visited by the choices dealers.. Gangs and other vested players would be able to target a market, running it down and pushing the good traders to other markets.. really let players and the gang warfare have an effect. Of course this might need certain checks and balances to prevent OP but i like the idea of economic warfare.
I love your idea Johnny. id just respectfully say that certain items should be impossible or very hard to find in a market.. guns/drugs and other player run economy items should remain outside the market and there shouldn't be a specific gun dealer or drugs dealer as such.. but i do like the concept of a clothing section of the market.. an themely electronics section.. a weapons market section.. etc.. etc...
To my mind this helps fullfil the end objective of having more and more of the economy of the game in the hands of the players and so should always be about facilitate more player to player economy by giving love to fixers/traders/couriers whilst also not impacting on other in game professions..
Anything that helps players create/craft stuff and facilitates player to player trade is always a bonus on things that cant be player crafted.
anyway just my two chyen worth.