PRICING ALGORITHM
Overview: Most of the weapons and equipment in Counter-Strike have had the same prices since the day the game was first released. These prices greatly affect the overall balance of the game. We at Valve know we're not alone in thinking that some of the prices in the game have never been exactly what they should be. (Uh, night-vision?) But rather than tweaking the values ourselves, we thought we'd rather let you decide. Coming soon in Counter-Strike: Source is a new system that sets the prices of what you can buy based on, well, what people are buying.
Starting on October 11th, the prices of weapons and equipment in Counter-Strike: Source will be updated each week based on the global market demand for each item. As more people purchase a certain weapon, the price for that weapon will rise and other weapons will become less expensive.
Gather player purchase data. Each week, the total number of weapons purchased world-wide since the previous week's change is counted. The purchase data is gathered directly from game servers. Every 24 hours, game servers upload a file to Steam listing the quantities of all items purchased over the course of the previous day.
Slice up the Money Pie. The new price for each weapon is based on the total amount of money spent on that weapon. The percentage of money spent on each weapon during the week is used to determine the percentage by which its price moves the next week. So if 10% of all dollars world-wide are spent on the Maverick M4A1 Carbine, then its price will increase by 10%.
A note about pistols. The purchasable items are split into two seperate groups: pistols, and everything else. This is an artificial segmentation of the economy designed to preserve Counter-Strike's "pistol round" -- the early period during which players can not yet afford the game's more powerful weapons. (If the pistols were included in the larger pool of prices, they would often become too expensive to afford during the beginning of a match.) Pistols are also given to players for "free" at the start of each round, which would artificially affect the economy.
Ups and Downs. In order to decide which items increase in value and which ones decrease, we order the list of all items based on the number of purchases for that weapon or piece of equipment for the previous week. We then split that list in half, with approximately 50% of global money spent above the line and 50% below. Items above the line increase in value, items below decrease.
A (somewhat) closed system. In Counter-Strike, each gameserver is its own instance of the game world. Unlike persistent "massively multiplayer" games, there is no open-ended economy. Until now, each gameserver presented its weapons and equipment for sale according to pre-set values which never changed. Now, the prices are dynamic. However, the total default amount of money available for players to spend on each server will be unchanged. At the start of a round, the default amount of money available for each player will remain $800.
It's all up to you. There is a massive community of people playing Counter-Strike, and for the first time the actions of the community are going to affect all Counter-Strike players. We're anxious to see the ways in which the game changes as a result of the global community of gamers exerting their influence. As always, let us know what you think.
And about those winning team joiners, I only play on pubs where you can only auto-select the team, and balances itself out with kill:death ratios every other round.
. I might install css again once this hits the game 
its out now