Definitely less than a thousand bucks or anywhere near. Piezo and the stripey fin ones fetch a little more, but not much. Counter-intuitively, the piezo version sounds a lot more lively and assertive than the Grabber pup one. Still, both a Grabber and a Victory Standard are much better instruments (the Explorer mixes parts from both, but they are both long scale and have maple or alder bodies).
I can't see these ever going up in value in a relevant way. They are just not very well sounding basses, have no name player attached to them and lack the mystiqe of the the early 80ies Flying V basses which are sonically nothing to write home about either, but trade much higher probably due to the higher craftsmanship and the Flying V legend. Those 80ies Explorers reek cheap in contrast. Gibson did much, much better with the "reissue" (in fact a completely different bass with the same body shape) from a few years ago. If you're in love with the Explorer look - and I can understand anyone who is -, then buy one of those.