If the independent is familiar with Honda then yes. If this is a chain store like a Purrfect Auto or Econo-Lube then no. Why do you think you need the valves adjusted?
Did they tell you what the codes is? Is the vehicle at the dealer or an independant? Does the engine run rough when hot or cold?
The information you gave me has helped a great deal. Believe it or not. The fact that the vehicle runs poorly when cold leads me to believe that there is a problem with valve clearance. At this point I would ignore the O2 sensor code and have the valves adjusted to start with. Albeit it is very unusual for the valve clearance to be out of specs at this mileage, it is not unheard of especially if you have had some engine work performed.
To answer your original question. A valve adjustment on this vehicle at the dealer should cost $215.00 parts and labor(At the most).
If you were to take it to an independent shop, you would expect to spend about $100.00 less. Keep in mind that you get what you pay for.