I have NIB GPS-710 and the 24'' extension. Never used. Never got around to replacing my old D700. Boxes opened when first purchased to inspect and have a look at it. Think I paid somewhere around $129 for the GPS unit. Can't recall what I paid for the extension. I'd let it go for $80.00 iffen you want it...I'll pay the shipping...US Postal money order works for me...
73, Todd KH2TJ
Would love to have one of the Green Light Labs units or something similar, but those are basically unattainable (unless someone here has one they want to part with).