Fair price--spark plug change?

What would you say is a fair labor charge for replacing the spark plugs on a Toyota 3L v-6 (1999 Lexus E300)? In dollars, or maybe labor-hours?

My labor guide shows $135.00.

I replaced the plugs on my wifes ES350. Those back plugs are a royal pain. Might be the same on your E300.

This is a transverse mounted V6 engine. Meaning you have 3 plugs on the front that are real easy to change and the 3 in the back are very difficult to replace. It involves removing some significant engine parts to even get access to the back 3 plugs. The Camry, Avalon, with V6 engines have the same problem. Most shops that work on Toyota’s do a lot of these jobs so shop around for some prices. You are looking at about 2 hours for labor.

Book time is 2.8 hours

Fair price in labor hours: book time, which is 2.8 hours.
Fair price in dollars: depends on the hourly rate in your part of the country, could be anywhere from $150-400.
Whoever does this also needs to quote you a plenum gasket, but not charge additional labor to replace it because the upper plenum needs to come off to replace the back bank plugs.