Received quotes between $600 – $2,600 to have a valve installed on my gas line for an outdoor grill, wondering if $600 is reasonable price?

Title says all. I know people need to make a living and I don't mind at all paying a premium for good work, but feel like the quotes I received for $1,600 and $2,600 are rip offs. Is anyone familiar with prices for plumbing services and can advise if $600 is a reasonable price to have a valve installed? All the job entails is installing a valve onto the existing main gas line so that I can connect an outdoor natural gas grill to it.