One dude on that reddit thread makes a joke about the elder dragon legends...
...before chronicles, you couldnt trade a black lotus for a nicol bolas straight up. Even though the lotus was 300ish and the bolas was...I think somewhere around 50-75 at the time? The speculation on him was insane.
I traded away a bunch of revised duals to a friend for arabians cards. Wasn't a good deal for me in the end. The duals were going for 15 each at the time, so it took quite a few duals to get the value up.
I remember when mirror universe was the highest value legends card...and before that all hallow's eve I think?
Guardian Beast was the highest value arabian card for a long time, then djinn, then library, now bazaar i guess? I picked up my bazaar as something some dude threw in on a trade because i was trying to grab arabian cards, and it was worthless at the time. Just something to make me happy and want to do the trade he wanted.
The local gaming store around here used to sell on scrye low. So one month, candelabra was at 20ish (maybe 22) high and 11 low...which at the time was a massive difference. The difference usually was only a couple of bucks between high and low. So I bought the candelabra. Good deal for me.