Seller nightmaretony has a rare Neo Geo Developer Cartridge up for auction and there’s currently 10 days left. The price is at $1000 with one bidder and the buy-it-now price is $5000. I don’t think anyone will end it for the 5k, and the auction has a reserve so who knows how much the seller’s willing to sell this for. The auctions over at GameGavel so if you haven’t seen it yet this will probably be your only chance to own the dev cart as I haven’t seen these pop up anywhere.
Seller says: “The rarest Neo Geo cartridge of all, a developer cartridge. Presently has Windjammer eproms on it, except for the sound sample chips, so there is no sound. Use it for creating Neo Geo arcade games.”