How much does this cost to the nearest dollar?

Nitrous Express Nitrous Oxide System, Proton Plus, Wet, Single Stage, 35-150 HP, 10 lb Bottle, White, Universal EFI, Kit
Nitrous Oxide System, Proton Plus, Wet, Single Stage, 35-150 HP, 10 lb Bottle, White, Universal EFI, Kit Nitrous System with 10 lbs. Model Number Item Package Dimension 28.0 L x 11.0 W x 10.0 H Item Package Weight 20.0 lb Manufacturer Nitrous Express Inc., Brand Nitrous Express, Model Nitrous Express - Proton Plus Nitrous Kit w/10lb Bottle Weight 20 pounds, model number Exterior Machined, Manufacturer Part OEM Part Rank Automotive 87344, Powersports Nitrous Kits 

Price is $551.00
Price: $550.95