balanced volume control

howzabout a dual MDAC?

Some of the others may scream, but think about some of the MDAC volume controls, specifically the TI/Burr Brown PGA2610 or Crystal Semiconductor CS3310. They have 2 matched sections which would work well for balanced volume controls. You can get parts cheap: most companies will give you a piece or two as engineering samples :)

Definately cheaper than $200, but these two devices are serially controlled, so a microcontoller would be convenient.