Wow! So are there are lot of high dollar titles remaining still? Or do you have those mostly covered?
A few weeks ago I went through the US list to see what was still missing. Out of the approximately 580 games missing, about 1/3 are sports titles, 1/3 are non-sports commons, and 1/3 are higher end games. When I say "higher end" games, I don't necessarily mean super expensive. Many in that group are around $15 to $20, but unfortunately, there are also several fairly expensive games that I'm still missing. As a general rule of thumb, I prefer to look for the more expensive stuff fist and save the cheap commons for last, but at the same time, if I can grab commons from lots, or find them for a buck a piece or less, I will always grab them.
I'm not sure how realistic getting a full set really is. Prices seem to keep climbing and fewer and fewer games are appearing in "the wild." But I still enjoy it and I will still continue to look for deals even if it take me another 10 years of looking. I still collect for other consoles as well, but outside of PS4 or Switch, it's pretty rare for me to buy anything else right now. I still haven't jumped to the PS5 gen yet, and I don't see myself doing that anytime soon.