Value of old ernie ball volume pedal?

Looking at an old ernie ball volume pedal input/output on the same side instead of up front like the newer ones. Are they collectible. How much are they worth?

Thanks,
Matt

Those early ones usually sell for less than used later versions, since they don't have the tuner out jack. I've seen them go for $40-$50 over on TGP, while the newer versions go for $65-$70.