Roulette CS:GO. How and from where the bots take the prices of the items?

Not exactly sure, but with the advent of the Steam API and climbed the sites with the roulette. Prices taken from the Trading platform, if the goods are not now, then remembered the last price. Most likely there is an opportunity for the portal administrator to set the price of a particular type of weapon. That's just have no idea about the frequency of roulette to the trading platform for matching prices.

We can guarantee a correct estimate of the value of things only when it is on the Steam community market, otherwise your subject may be misjudged.

Think here is the answer to your question.