Ripped off or Taken Good care of?

Newbie, 2008 Ram 1500, 115,000 miles. Charged the following when trying to pass state inspection.

Replace Oil Pan gasket/Spark plugs $365 Labor
Oil pan Gasket $75
Spark Plugs 110
Rear Differential service $90
Power Steering Flush $90
Fuel System Cleaning $90
Purge Solenoid Labor $95
Labor Purge Solenoid $45

After this light still on but I got it off and passed inspection by disconnecting battery and putting fuel additive in tank.

Welcome!

Hard to say without knowing which state and whether it was safety or smog at a retail mechanic or stealership.

Even with what you haven't told us yet, $800 bucks for an annual inspection seems like a lot...

If the truck was running badly and couldn't pass smog then plugs and maybe even fuel system cleaner make sense. Price and labor for plugs is not ridiculous and replacing pan gasket is a safety and oil pollution hit in some states--in fact, if it was leaking oil anywhere that might fail you in some states for safety and/or smog.

Hard to see how these were required:
Rear Differential service $90
Power Steering Flush $90


Fuel system is a $15 can of Seafoam and 20-30 mins. Not counting soak time, but $90-100 is about typical charge.
Unless it was running badly (smog) it probably was not essential, however.

The diff and steering might have been due, but unless leaking shouldn't have anything to do with passing inspection.

I'm suspicious that you got the stealership treatment for about $300 of the cost. But that doesn't mean it wasn't maintenance that should have been done.

I might have a different opinion if I knew the rest of the story--sounds like you have a fuel system vapor leak that you are hiding using the battery trick.

The state is Texas. the code that failed was for gas cap or other leak. Vehicle was not running poorly.