system
A chat on subreddit /r/NoStupidQuestions
human
A lot of the costs depends on what you already have and what your minimum standards of "gaming" is. Some people have a computer but no TV. Others pay for like 6 streaming services instead of 1. Some people have time, but not in solid chunks. Some people have a decent TV and a workable computer, and have overall enough time... but don't have it in solid chunks. Preparing for a raid is hard when you can't guarantee no interruptions for any particular chunk of time.

But there are a lot of games that require potatoes for a computer, are single player, and if bought on sale will give you hundreds of hours of fun for less than $30.
gpt
There’s thousands of great games from the last 20 years that can run on integrated graphics these days, don’t even have to only play AAA games. 

Honestly I wish the Steam Deck was in a better state so I could recommend it for someone to get into PC gaming, but ATM I’d only recommend it for someone with a good technical or troubleshooting skill set.