There were quite a few Apple 1s made - Woz was selling them as DIY kits. This is an actual Apple motherboard though - it's silkscreened on the motherboard. It's ultra, ultra rare.
If anyone here is a collector, let me point you towards another rarity that pops up on eBay from time to time. The so-called 'Mark Twain' IIgs. It's also known as the ROM04 IIgs. It was much closer to being a Mac than the ROM03s were, and didn't make it out of the prototype stages although a few slipped out. They're fairly cheap now, but they're going to be uber-valuable someday.
EDIT: Lisas that wern't converted to Mac XL are probably going to be up there too, someday.