The Vision Ring is pretty much superior to the Balance Ring in most ways. The flat bonus to Acc. and Ranged Acc. is better then an extra +1 Dex.
Likewise, the Mighty Ring beats the Courage Ring by a sizeable margin. It would take an additional +8 Str. to get that +4 Attack/Ranged Attack from the Courage Ring.
The downside? No switching, and the effect dies when you zone, leave the game or, like food, are killed. These were going for 30k on Cerberus, but I didn't think anyone would buy them while they cost more then Courage/Balance, so I cost them at 20k and still make a decent profit.