I have two SOS Decometers I may decide to sell. They both are in excellent condition and were never used and still have the protective powder on the rubber straps. I got them from a dive shop before it was liquidated. One is in the original box with instructions. The other is in the black egg without instructions. Anyone have any idea what they might be worth? Just a ballpark figure? I also have two Dacor professional model 3106 or 3107 LCG capillary depth gauges new in box with instructions. Any guess on their value?