I was around when the CoX Market launched and right away I knew there would be a problem. You had hordes of Vets with PILES of cash and nothing to buy. This drove some prices to insane levels right away. Things eventually settled down but newer players coming in after the Market launch often felt intimidated (the lousy interface didn't help) or frustrated and opted out. This meant fewer players participating in the Market and even some players leaving the game.
TPP will hopefully have a Market at launch. However I want to avoid some of the more blatant things that might turn players off and drive them away.
1) Price History: Make this a choice between 5, 10 and 20 sales. Cheap stuff with little fluctuation players will leave at 5 sales but the million-plus stuff they can watch more carefully. The longer sale history will make it tougher to artificially inflate prices.
2) Keep the glitz in and around the Market to a minimum to prevent lag. Suppress Powers, keep the shiny stuff outside. Perhaps even make it instanced.
3) Never let items run out. In the real world when there is a shortage of something, someone makes more of it to grab market share. So why not do this behind the scenes in the Market? Anything that begins to run out (Commons to 10, uncommons to 5 and rares to 1 for instance), the Market restocks from a non-player source. Now these new items will come in at MUCH higher prices due to scarcity but there will ALWAYS be at least one of whatever you want if you're willing to pay for it. This guarantees that the mad inventor who HAS to have the Purple Widgit can get it...if he has the cash.
4) Keep item scarcity in tiers. This has more to do with Inventing but here goes: Common drops should be used for Common recipes and ONLY Common recipes. One problem with CoX was that many high-ticket recipes called for drops that were only available at lower levels. This meant that new inventors were competing with 50s for the one thing to complete their Wing recipe. I firmly believe that the top-tier recipes should only require top-tier drops.
5) Don't put the cool non-combat stuff in the ultra-rare drop category. Remember when Wings first came out? Many players never got them because they dropped so seldom. Those players who clocked 40 hours a week sold the ones they had for millions. Yes, let the buyer beware, but this is for a costume piece, not a Stealth IO. When they upped the drop rate for wings the only players hurt were the greedy ones selling surplus recipes for millions. The rest of us were thrilled.
I know that the gaming community will insist on a Market and as much as I opposed it at first in CoX it turned out to be lots of fun. However I want it to be something everyone can participate in, not just a select few.
I remember when Star Wars was cool...a long, long time ago...