So everyone here is saying get him a PS5, I disagree.

You mention that they're expensive so I assume money might be a factor. In that case I'd definitely advise the PS4. PSVR (PlayStation VR 1 only, the second iteration is PS5 exclusive) is compatible with the 4, plus God of War (both the first "new" one and the sequel Ragnarok) and Spiderman (the first "new" one and the miles Morales stand alone expansion, not the upcoming Spiderman 2) are both on the PS4, as well as a bunch of other PlayStation exclusive singleplayer story based games (like the Last of Us 1&2, Horizon: Zero Dawn, Uncharted series, etc).

So since you also seem very unfamiliar with gaming consoles in general here's a basic breakdown;

-Microsoft makes the Xbox and Sony makes the PlayStation,

-The Xbox Series X (XSX) is a current generation Xbox console and therefore has all of their newest releases available,

-The PlayStation 5 (PS5) is the current generation PlayStation equivalent,

-The PlayStation 4 (PS4) is the last generation PS, up until late 2020 every single thing released for PS was on the PS4, and even for the past 2 years I'd say most things still came out on it,

-Probably upwards of 90% of all games released are on both consoles,

-Each company does have some exclusives (Xbox has Halo, Gears of War, Forza. PS has God of War, Spider-man, the Last of Us) which are only on their own console,

-PS has VR capability through the PSVR while Xbox does not

So basically, if you have one console than the other is limited in what it actually provides. If you don't have a lot of money to spend on bonus shit I say the last gen PS4 gives a lot of the benefits and a LOT of PS exclusives that have previously come out while saving likely a bunch of cash.

Personally (as an Xbox guy) I generally wait till the PS has gotten way cheaper years after it releases (and has updated smaller versions come out) before grabbing one for the exclusives.