Roush Stage I - Core Components V-8 $6,020.00 + S&H
Mustang stage 1
The Roush Stage I Mustang was designed for the Mustang aficionado who wants to stand out from the crowd. The Stage I incorporates the Mustang GT engine, with upgrades that include a full body kit and a new exhaust system. The Stage I’s side-mounted performance exhaust system provides a high performance roar with a very cool look. 17-inch wheels and tires and a lowered suspension (via new coil springs) for the V-6 model drop the car's center of gravity for better handling. Appearance upgrades, including an air dam, side skirts and dramatic rear wing, immediately identify this Mustang as a breed apart.
Roush Stage II - Core Components $9,860.00 + S&H
The Roush Stage 2 Mustang package contains the 260 HP producing SOHC V8 and other core components offered in the Stage 1 package, with stunning cosmetic and suspension upgrades. The 18 inch alloy Roush wheels make an impressive visual statement. The suspension upgrade, with beefy anti roll bars, higher-rate springs, new lower control arms and Billstein shocks, sends a signal that this a vehicle for serious drivers. This dynamic combination allows nearly 1.0 g in lateral acceleration. Available options include the extremely comfortable Roush Sport seating system.
Roush Stage III Sport Core Components $17,645.00 + S&H
Jack Roush issued the engineering team at Roush Industries a challenge - "Design and engineer a true high performance, reliable and exciting Mustang, true Muscle Car, and I will see that America will get it." They delivered the Roush Stage 3 Mustang – a winning combination of affordable performance and OEM quality - designed, engineered and manufactured with the motorsports legacy of Roush Racing and the technical expertise of Roush Industries. The Stage 3 combines increased horsepower and torque with carefully engineered changes to suspension, braking, and body systems. The result - unbridled performance with the superb handling of a true thoroughbred.
The Stage 3 is offered with three exciting packages:
The Stage 3 Sport package includes a Roush 4.6L SOHC Supercharged Powertrain, Roush PBR Brake system, and dramatically styled exterior package. With the well-mannered handling of a road car and the raw muscle of a racecar, the Sport transports you from the ordinary to the extraordinary with dramatic style and exhilarating speed.
The Stage 3 Rally version includes all the features offered in the Sport package, then adds the sophisticated Roush V-8 suspension system, 18” wheels, racing-style alloy pedals and white-faced gauges, all thoughtfully designed and engineered to balance performance and ride quality.
The Roush Stage 3 Premium puts the ultimate driving experience as close as your dealer’s showroom. In addition to the dramatic styling, powertrain, suspension and interior upgrades offered in the Sport and Rally packages, the Stage 3 Premium takes comfort and performance to a new level with an impressively powerful braking system, and luxurious leather seating.
The Stage 3 – a new standard of performance.
The above comes from the Roush Site. From what I can see is you are mainly "Paying For the Name" There is nothing special with 90% of the Roushes out there on the street IMO. Around here I have beaten them right and left with my GT and I didn't have as much invested in the GT as the comperable Roush kit.
__________________ 2004 DSG Mach 1 w/IUP 5 speed (Born on Date: 10/09/03)
Dyno - 1/28/04 (1300 miles)K&N Drop-in Filter, SAE - 273.8 rwhp 302.5 rwtq
Dyno - 3/6/04 (3400 miles)K&N AirCharger, SAE - 282.5 rwhp 312.6 rwtq
Dyno 4/22/05 304rwhp 326rwtq | 
Roush Mustangs 
