Not gonna tell where, but you can buy rF2 for $2. AMS2 for $5. At least the cd-key for a steam purchase.
I've been in sim racing since 2013 and you would not consider me an rF2 "fan". rF2 was the first sim I bought (for $80) just because I read an article about the best sims and rF2 was in the top3 (with iR and Simraceway which doesn't exist anymore) and I didn't know anything about sims back then.
So rF2:
graphics: I think it can look superb in cockpit mode with later added/updated content, either official or modded tracks. I think even the rainy weather looks as good as in AMS2 even though I never race in rainy weather. But it usually doesn't look as good in outside camera modes and can look horrible with older or unfinished contents and with lower graphics settings. The lighting in rF2 is bad that's why you see (or used to see) a lot of rF2 screenshots in the sunset. Even the intro of the game is in the sunset
FFB: Mr. Ogonoski said it's not above other sims, I think it is. You just have to adjust the car specific FFB multiplier. I just ran a race against AI in AMS2 and in rF2 on Bathurst with the GT3s and the FFB in rF2 is much more enjoyable. The FFB on iR is a joke, AC/ACC is close but not as good as rF2.
physics: no idea, I've never driven any of the cars IRL I drive in sims but not as sketchy as iR for sure
sounds: usually horrible. This is the sole reason I race less and less in any sim. If you compare the sound of a car in rF2 in cockpit view vs a real car, rF2 sounds are usually pathetic, they all miss the feel of power of the engine or however you wanna call it (the vroomvroom, the scream), they sound horrible, horrible, horrible with rare exceptions. Total immersion killer for me, usually I feel like I'm driving some stupid vacuum cleaner or listening to some racing game from 1985. Exception is the F1 cars, they usually sound good, too bad I don't like F1 cars.
AI: it's a hit or miss, depends on the track. If it's official content it's usually good. If it was made by a modder it's less likely to be good but if you are good at modding AI paths you can always help the modders out.
online racing: dead... since inception.
price: now if you are really about GT3 or GTE cars it's best to buy DLCs, but you don't have to. There is the Enduracers mod for free. Porsche Cup car the same. I for one am pretty bored with GT3/GTE cars, they are boring to drive and every other sim have them so I rather look for other types of cars.
If you like Formula cars there are a tons of mods and official cars you can choose from.
If you like touring cars then it's harder, there are some mods but I'm not sure about their quality.
Oval racing: official cars, tons of modded tracks, some with questionable AI, couple days ago I ran few good races at Richmond vs AI.
About tracks: the workshop has a ton of tracks, if you pick carefully (ie. finished or updated after 2020 and v1.0 or above) they can be very good. You don't have to race Le Mans or have to race the Nordschleife. I must admit I'm not a fan of Sebring (the track itself, I don't like flat tracks) but the Sebring made by S397 is superb mainly because of the bumps. The workshop is full of F1 tracks (I hate almost all of them because they are usually flat
) so the game doesn't lack in that department and there are a few US tracks too.
So all in all it worth $2.