In my opinion, nothing has ever come close to the rich economic system that emerged naturally in Diablo 2. Maybe it just hit me at a good time in my life, towards the end of high school.
I spent probably half my time playing that game just doing arbitrage trading. For example a sorceress or necromancer would always give you 4-5 Perfect Skulls for a Stone of Jordan (SOJ) ring, and you could pretty easily buy an SOJ from a barbarian or amazon for 3-4 Perfect Skulls. Through nothing but these trades I was able to go from a couple SOJ (the most valuable 1x1 item in the game) to about 40 or 50 over the course of a few months.
My favorite AH score was a max stat level 3 chest piece that I sold for $25.
That piece was good for 5 or maybe 10 minutes of gameplay at the start of the game.
I knew it was a premium piece for that level and type. I knew they didn’t stay on AH long. That said, I didn’t want to compete with all of the lower price point folks, so i set the price to something absurd just to see what happened.
I have no idea why they bought it.
I had much better late game stuff for sale for much cheaper that never sold. It was a strange market — I’m glad it is gone.
D3 RMAH was bad because D3 was bad. At that time there was basically no itemisation, everything gear was basically dps/main stat/trifecta. D3 was so bad that the fix was to remove trading completely and never been brought back.
People traded D2 items for gear, runes and/or real money for decades, there is no problem and the game is alive for well.
I mean, the real improvement to D3 was they massively upped the drop rate of rare items, which "coincidentally" happened when they stopped taking a cut off people selling their rare items for real money.