Heres the specs, if I grab him this do you think it will keep him busy well me and my machinist build the other one. 
$800, he wants to buy it, but with the build I got going should I let him waste his money?
    * THIS TURBO KIT DOES NOT INCLUDE THE DOWNPIPE,YOU NEED IT TO INSTALL COMPLETELY.
    * All PARTS ARE BRAND NEW IN BOX. WILL GIVE YOUR CAR 20%-50% HP.SUPPOSE GAIN 100-150HP, CAN UP TO MAX 350 HP FOR THIS KIT.
    * ALL THE PARTS ARE IN THE PICTURE,INCLUDING THE HARDWARES FOR INSTALLING, NO INSTALLATION IS INCLUDED. PROFESSIONAL INSTALLATION IS HIGHLY RECOMMENDED.
    * KIT INCLUDES:
    * T3/T4 TURBO CHARGER:
    *
       3" Inlet Diameter, 2" Outlet Diameter, Compressor : 50 AR, Exducer : 3", Inducer: 2".
      Turbine : 63 AR , Exducer: 2.2"  inducer: 2.6". Max Up To 35 psi power performance output. CNC Machined flanges, T3/T4 Flange, Max Power: 350HP - 400HP.
    *
      CAVALIER CAST IRON TURBO MANIFOLD:
    *
      BLACK CAST IRON TURBO MANIFOLD,HIGHER RESISTANCE TO HEAT,DIRECT BOLT ON TO YOUR ENGINE.
    *
      ALLOW POWER STEERING AND AIR CONDITIONING,FITS WITH T3/T4 FLANGE TURBOS AND 35MM/38MM WASTEGATE.
    *
      INTERCOOLER:
    * FULL SIZE: 28" x8" x 2.5" WITH 2.5 INCH INLET/OUTLET.
    * LOW PRESSURE DROP - LARGE COOLING AREA - EASY INSTALL - TUBE AND FIN STYLE.
    * PIPING KIT:
    * Made of 6061 Aluminum. 2.5 inch Diameter Piping Kit With High Quality Silicone Couplers And T-Bolt Clamps.
    * The Couplers Will Not Split Easily + The Clamps Will Not Strip Like The Cheap Kind.
    * Strong & Tighter Fitting Use Hair Spray Between The Pipe And Coupler.
    * Mandrel Bend 2.5 Pipe(As Shown As Picture) For High Flow And High Horse Power And Better Turbo Response Power.Some Cutting And Modification Required!
    * 38MM WASTEGATE : 
    * ALL STAINLESS STEEL HARDWARE, MATING WELD FLANGE ARE 304L 
    * DUAL PORT,ACCURATE BOOST,ULTRA DURABEL DIAGRAM(DIAPHRAM)
      COME WITH 7PSI,11PSI,15PSI WASTE GATE SPRING(FULLY ADJUSTABLE),YOU CAN ADD THE SPRING TO GET HIGH PSI.
    * ACCURATE BOOST CONTROL AND HIGH QUALITY APPEARANCE
    * BOOST CONTROLLER:
    * Allows Adjustable Boost PSI Settings, Light Weight Design To Be Mount Under The Hood. Hardware Is Included.
    * Manually Control turbo boost up to 30 PSI.
    * OIL RETURN LINE:
    *
      HIGH QUALITY ALUMINUM.THE RETURN LINE IS 17 INCH LENGTHM,INSIDE DIAMETER IS 0.5 INCH.
    *
      HELPS CIRCULATE OIL FROM THE TURBO TO THE OIL PAN, WORKS ON METAL OIL OANS ONLY.
    * OIL FEED LINE:
    * 100% Brand New, High Quality, Never Been Used Or Installed!
    * The Oil Feeding Flange has Restriction build in, offers proper Oil Feeding to the turbocharger.
    * The Length Is 37 Inch.
    * BLOW OFF VALVE BOV:
    * CNC Billet Aluminum, Dual Stage Handle, High Boost Power,Easy Mount Piping Set Included For Bolt-On.Including Bov Blow Off Value Flange.
    * Fast Fesponse One For Low And High Boost Pressure.
    * OIL CATCH TANK:
    * High Quality Polished Made Of Billet 6061 Aluminum, And TIG Welded W/ Billet Aluminum CNC machined.
    * Will Ensure Better Performance And Better Mileage On Your Engine. Mounts Above Your Valve Cover And Ensures Excess Dirt And Oil Does Not Get Inside Your Engine.
    * Dimensions: 6.25''x3.25"x3.25" , Holds up to 750ml.
    * FUEL PRESSURE REGULATOR:
    * HIGH QUALITY,LIGHT WEIGHT POLISHED ALUMINUM, INCLUDING THE HARDWARES AND HOSES FOR INSTALLING.
    * MAX UP TO 10 PSI ADJUSTMENT TO MANAGE YOUR FUEL SYSTEM REQUIREMENT, INCREASE FUEL DELIVERY BY RAISING PRESSURE, GAIN 5-10 HP.