Shop says new piston rings required. Am I being conned?

[His Dudeness]

Taking the head off and replacing valve seals is doable at home.  You need a suitable torque wrench and a valve spring compressor.  Read the manual a few times so you know the procedure and how to time the engine. If you go slow and careful you should be able to do it. The hardest part would probably be getting the exhaust off without shearing studs.