Does runescape count?
Me and my friend wanted to kill the kalphite queen. He used to cheat and buy money from gold farmers, I never did because my parents wouldn't let me and I didn't really feel I needed to.
I managed to save up 5 mil to buy full veracs, which was about 5.2 mil at the time. Just for referance I made my money picking flax and spinning bowstrings at a rate of ~150k an hour. Making 1 mil must have taken me about 1-2 weeks of playing time. Making 5 mil took me about 1 months or so.
So there I am, falador garden world 2, trying to haggle with my 5 mil for full veraks. Suddenly I see some guy selling full veraks 4.7m and I jump at the chance.
He "has another buyer". He keeps logging off, making me increasingly frustrated. Some guy offers him 4.9m. I put up my full 5M for "full" veraks.
Turns out I actually purchase veraks, but 2x 300k body plates, instead of the 2.2m helm. You needed the full set for the set effect bonus or else it was pointless.
Basically I got scammed out of something like 1.5m, a solid 2 weeks or 30 something hours of flax picking spinning and grinding.
Man I was pissed.