This would be adds for Civs to place items up for sale at a slight cost.
ex.
Car, Used
White Skoda for sale no damage comes with full tank of gas. $8,000
by: Mike Barton last on: 09/03/10 @ 10:45 CST
Car, New
Yellow Hatchback made from factory $10,000
by Mike Barton last on: Now
It would be a list somewhat like that. I hate trying to sell my service or items that I don't use any more via chat its a lot to type and its sorta spam and someone that was going to but a Hatchback notices that there's a new one for sale and its cheeper than Rattletraps and he is online. I mean I was looking for a Roadrunner type car and most people weren't selling or going to give me a ride so I had to buy a bike cuz i didn't want to leave my Skoda there and ride all the way up there to buy it. Civs could only sell to civs and cops could only sell to cops. Also for the sale of cars would have to be custom coded to ware the buyer can get a key and be able to store it and the seller would loose there key and not be able to sell. to avoid scams there could be an 'Exchange' tool were buyer puts in money and seller puts in car seller hits 'Accept' and Buyer can hit 'Cancel' if its wrong car for he's going to screwed or if everything is good click 'Accept' and change happens Seller looses Key and Name on Registration and Car and Buyer looses 'X' amount of money and transfer is done everyone is happy.
Pricing would be by day or hour based on a % of sale price. ex. $500 item cost is 5% for 1 day listing costing seller $25 for listing. $500 item cost for 7 day listing is 11% costing seller $55. if item is $80,000 for 1 day listing is 8% costs seller $6,400. For a $80,000 item for a 7day listing is 14% costs seller $11,200. Or what ever rate you think is reasonable i pulled that rate out of the air.