I have a 2003 v6 Blazer with the following problems:

Engine light on - Blinking at times (misfire on cyl 3)
Rough start and turnover
Strong Exhaust smell (not normal)
Idols very rough/shakes
Accelerates roughly
Not responsive sometimes when highway diving and given gas

I took it in to a Chevy Dealer Service Dept, here is their diagnoses and work order:

Fuel Regulator is faulty and 1 Injector is leaking

Parts:
Spark Plugs - 6
Fuel Regulator
Bank 1 02 Sensor
Replaced one Bad Fuel Injector
Full Fuel Injector Cleaning
All Related Seal Kits
Faulty Cat Converter - Replaced under warrantee
Nut Muffl - Replaced under warrantee
Pipe - Replaced under warrantee
Gasket - Replaced under warrantee
Seal - Replaced under warrantee

I now have the truck back and it is running great.

My question is, what should I have paid for this?

 

You likely paid dearly... I am not one to succumb to dealer repairs, but the exhaust I would have had them do if it was under warranty.

I would have replaced the entire spider which was likely cheaper than them replacing one injector, the FPR, and doing an injector cleaning considering both labor and parts.

I purchased the new MFI spider (PN 12568332) which included 6 new injectors, a new metering body, all applicable o-rings/seals, and a new FPR for $220 from my local dealer. You can expect to pay anywhere from $200 to the $300 MSRP shown on GMPartsDirect.com (which lists it at $170 +s&h).

The spark plugs and O2 sensor were likely double the going rate for AC Delco products from elsewhere (RockAuto.com, etc).

And I could only imagine what the shop rates would be when you stack up all of the various repairs.