Based on recent premium paid for the acquisitions of Activision Blizzard King and Zynga (around 50%), I added $50 to the current market cap of many public game companies to get a rough idea of the money that would cost to acquire them completely, even if it isn't needed to buy their 100% to control them:
- Tencent $604.11B
- Netease $94.8B
- Nintendo $77.88B
- Sea (Garena) $63.2B
- EA $54.57B
- Roblox $34.8B
- Take 2 $31.7B
- Nexon $29B
- Bandai Namco $24.8B
- Unity $16.25B
- Embracer $13.14B
- Konami $11.28B
- Capcom $8.9B
- NC Soft $8.6B
- Koei Tecmo $8.46B
- Square Enix $8.25B
- Ubisoft $7.8B
- CyberAgent $7.53B
- Netmarble $6.74B
- Perfect World Entertainment (Chinese film + PC and mobile games) $6.12B
- Sega Sammy $5.52B
- CD Project $3B (its market cap is $1.99B, was $7.42B in 2020 due to Cyberpunk hype before release. Its current price is still way overvalued)
- Paradox Interactive $2.82B
- DeNA $2.5B
- Mixi (mostly mobile games for Asia) $1.82B
- GungHo $1.8B
- Gree (Japanese mobile games for Asia + anime) $1.58B
- Huya (China's Stadia) $1.2B
- Team 17 $1.14B
- Frontier Developments (devs of Elite series) $1B
- Remedy $0.51B
- People Can Fly $0.48B
- Marvelous $0.45B
- Focus Home Interactive $0.39B
- Devolver Digital $0.41B
- 11 bit studios $0.36B
- Starbreeze $0.06B
- Atari $0.06B
We have to consider a few months ago Sony rised their mid term budget for acquisitions, investments or Sony stock repurchases to 4 trillion yen (~$30B). We have to consider that only a part of it will be for acquisitions, and it's for the whole Sony and that only a portion of it will be for gaming. And also "medium term" for a corporation like Sony means like 2-3 years.
So I assume that Sony would only spend this FY maximum around $10B on gaming acquisitions, maybe $15B being optimistic. When time ago they did set a $18B budget for investments, acquisitions and stock repurchases and spent over 10B of it, around 40% of it was for gaming.
Regarding companies not publicly traded like Valve, Epic or ARC System Works, people can make estimations of their value or cost but this means nothing because their major stakeholders freely decide the selling price.
We also have to consider that Sony should see them as a good fit and that their major stakeholders would have to want or need to sell and see Sony as a good fit. And the acquired company isn't of the same country than PlayStation/Sony (Japan) then the government of the acquired company could block the acquisition if it's a key strategical tech company for their country, something I could see it happening if trying to buy the most valued companies from China, USA or Korean companies but Sony can't afford at least most of them.
This budget doesn't mean Sony can't afford to spend more in acquisitions: it means they told their investors that plan to spend aprox. that money on a certain range or time. To spend more than this budget, but to do it right Sony could review it and informing their investors before making such acquisitions. And when they review these budgets and announce it is when announcing their fiscal year report in around May. With that I mean that if they review this budget to increase it would be in May 2023 or May 2024. So I wouldn't expect Sony to spend above $10B or being optimistic $15B in gaming acquisitions this FY.