Taking into account the cost of materials and the financial requirement of launching the weapon into the space, the breakdown only goes as far as estimating the cost of building the weapons shell.
However, according to British party site Twizzle that cost may have been a conservative estimation. Twizzle has put together an infographic breaking down the cost of building a death star, estimating the total cost of construction to be $22,452,000,000,000,000,000. In addition to reaffirming the administrations policy against blowing up planets, Shawcross also explained the estimated $850 quadrillion cost of construction was too high a burden for taxpayers. Arguing that the project would create jobs in fields including engineering and construction while strengthening national defense, fans were disappointed when official science and technology adviser Paul Shawcross responded by rejecting the petition.
Back in 2013 Star Wars fans launched a petition on the White House website calling on the Obama administration to begin construction on a real-life Death Star, the Imperial superweapon that will be at the center of the plot for the upcoming Star Wars spin-off film Rogue One: A Star Wars Story.