The pinball itself is a typical Bally of the era. Simple and fast. Not a player's machine at all. If the game had a different theme, it would be as valuable as a Mata Hari, Harlem Globetrotters or Supersonic.
To put it simply - The game is valuable and collectible SOLELY because it is a "KISS" theme. Most pinheads won't buy this machine as it is overpriced. Driven to the high price by KISS fans. Keep in mind, eBay Australia is not a useful tool in determining its value. I've seen junk KISS machines sold for $7000, and better machines for $2500. I am a self confessed MASSIVE KISS fan (just do a search on this site), and I have been since 1977. As a band, they have a huge fanbase in Australia. I am asked "Have you got a KISS for sale" at least once a week. Very sought after machine, but most machines are well worn these days. German KISS machines are in Australia, and are usually bought by fans that cannot afford the USA version.
By "Headboards" - do you mean backglasses ? The market is not as big as USA or Europe. Australians are more interested in GAMES. It is a buyer's market at the moment as supply is far greater than demand.