Best way to spend $50 to upgrade my son's gaming rig (details in post)?

• Asus TUF Gaming B550-PLUS (WI-FI) • AMD Ryzen 5 3600 • G. Skill Ripjaws V Series 2x8 • MSI Ventus GeForce RTX 4070 12GB • Corsair HX 750W PSU Edit: I don't know if it makes a difference, but he's connected to a 4K screen. I don't recall the refresh rate off the top of my head. The 'main' gift is jumping from a 5700 XT to the 4070. I can double his RAM from 16 to 32GB for $50, but I don't know if it will have any performance impact. His homework computer is upstairs, so this is used almost exclusively for gaming (multiplayer FPS and VR on a Valve Index). Isn't 16GB more than enough for that and leaping to 32GB would be unnoticeable? Would the money be better spent elsewhere (his Steam wallet is taken care of, so I'm thinking hardware)? I got myself here because my work PC has 32GB as do some of his friends' computers, so it's something he thinks will be better -- but I'm wary of a $50 placebo if no AAA or other title would make use of the extra RAM.