Whats an 1 in 7 Etek 1 worth?

[Rat]

have my Etek 1 that i might sell to raise funds (last resort though) its one of 7 in the world in blue and black though i've added a gold feedneck.

also has a unitech blue and gold barrel aswell as the stock black barrel.

any ideas on what its worth would be great.

only put about 2/3 boxes of paint through it and its still in mint condition.

thanks folks