Sources: Overwatch League expansion slots expected to be $30 million to $60 million

London Spitfire players embrace on-screen following the team's 3-1 victory against the Houston Outlaws during the Overwatch League. Robert Paul/Provided by Blizzard Entertainment

Activision Blizzard will price expansion slots for the Overwatch League between $30 million and $60 million as the company continues to negotiate with prospective buyers, sources familiar with discussions for those spots told ESPN.

The exact price for each slot will depend on several factors. Among the factors are general population of the area where the team would be based and the number of players who play Overwatch within that region, sources said. Additionally, if a single market has multiple interested buyers, the price is subject to being raised as those suitors bid against one another, according to sources.

The 12 franchises taking part in the inaugural season of Overwatch League, which began in January, paid $20 million each to Activision Blizzard for those franchise spots, which were sold in the summer and fall of 2017.

The increase is in line with a number of factors, including a significant spike in quoted evaluations of esports organizations, particularly those that have franchise slots in both the Overwatch League and the North American League of Legends Championship Series. Last summer, top North American esports organizations, such as Cloud9 and Immortals, were valued between $100 million and $140 million, and some organizations are now valued at around $160 million to $200 million, according to sources.

Activision Blizzard will hope to sell anywhere from four to six expansion slots in the next season, with targets in North American and international cities. Sources said several organizations both endemic and not endemic to esports who did not buy in last year have a fear of missing out on being included in the top franchised esports leagues.

In 2017, some potential buyers thought an unprecedented $20 million buy-in price -- the highest among all esports leagues -- was too large a financial commitment to a product that did not exist.

That feeling has reportedly now changed. The Overwatch League has run for three stages so far from January to May, and the product has averaged around 80,00-170,000 concurrent viewers on its English-language Twitch broadcast, according to TwitchTracker. Opening day of the Overwatch League drew in more than 400,000 viewers. As for sales, the Overwatch League has gained close to $150 million in sponsorship and broadcasting rights deals, according to league sources. Among those is a two-year, $90 million Twitch deal, a multiyear, $17 million HP Omen agreement and a multiyear, $10 million Intel contract, as previously reported by ESPN.

Current Overwatch League ownership includes New England Patriots owner Robert Kraft; Denver Nuggets and Los Angeles Rams owner Stan Kroenke; Philadelphia Flyers parent group Comcast Spectacor; and Sterling.VC, the sister company of the New York Mets. Cloud9, Team Envy, Immortals, Misfits, NRG Esports and OpTic Gaming also hold slots in the league.