Running a gas line to fireplace

There's a gas line that runs through the attic no more than 6 feet from my chimney (single-story home). I'd like to run a gas line to the fireplace, which as far as I could tell would entail putting a tee into that gas line, running a pipe towards the chimney, then down through the wall along the chimney, then a valve, then into the fireplace. That's about 20' or so with 2 turns, and the wall is panelling which I can easily remove and replace.

I'm a major DIY'er but I leave the potentially fatal stuff to the pros. I just got a quote from a licensed plumber who said it would cost $600 -- and I would have to hire someone else to drill a hole through the chimney!

I have to say, I was really shocked. Granted, it's working in a stuffy confined attic for a few hours, but it just seems so straightforward, routine and simple to do -- is his quote reasonable? I was expecting like $300 or so.

Based on my experience, its reasonable. I had a similar length run for gas and water and got bids from $1000 - $2000.

$600 sounds reasonable.

I'll do it for $ 595.00

A lot of people would unthread the pipe from one side, make the cut, thread it, then reassemble from the end again.
I used to do a bit of gas piping, but it was never my favorite thing to do.

When he is done, he will need to re light the other appliances too.
If he's pulling a permit, there is the time for that, the inspection, and then making it live afterwards.

It can involve a few steps.

There is more to it than you think. The valve has to be the correct one, and its location is specified in your plumbing code. I may only take $600.00, but if I were giving you a set price, it would be more than that in case I ran into unforeseen problems. Just cutting and threading the line in the attic is not a picnic.

Thanks for all the feedback. I feel confident now that it's a reasonable price. Still, it will have to wait!