a friend of mine saw the lot in a retro shop in Osaka last summer, they were asking no more than 20.000 yen for all the green labeled carts...you know, among loose carts, almost junk..he also thought it was garbage and passed:
just to give you an idea of how much they were valued in the DenDen Town shop selling them (you can see the minasanin the middle, same bent label, he just flipped it back)
Edit:
speculating a bit:
it seems to me those carts (EPROM, as mentioned in the development manual) were used for beta, almost by the end of the development process (compared to a prototype) like showing the game at shows or sending it to magazines.
Prototypes (early stage development/concept) have been seen in different carts (also mentioned in the dev manual) with PCMCIA storage, usually needed when changing the code a lot.
So to say, there is quite a possibility that the code in the green labels could be identical to the final release...the seller should at least post a unibios CRC otherwise it could be really the most expensive label ever bought..
(an oh, IMO, the real value is no more than 500$)
Edit 2: ...I asked the seller to post the CRC