I'm shopping for a portable player that has a balance control priced somewhere between $200-400.
Due to hearing loss on the left I need 6 to 10 db extra on that side depending on volume level. Actually I only need the boost from 250hz to 3khz, but precise parametricEQ is a lot to ask from a portable. In any case, without a balance control it's just not worth switching from my iPhone that does have it.
An added benefit is line out from a really good DAC capable of 24bit / 96k.