parts will cost you...
under $60. ASSUMING you fix via the TAB method. That's for a new gasket, front seal, spare pin, and a tube of Cummins Silver gasket sealer rtv.
I have air tools. I am not a mechanic. My first ever fix took 4 hours. Getting the new seal in the timing cover took 1 of those hours... I was new here. Plus I removed and re-torqued the other bolts while I was in there. My second and third jobs (for friends) took 2. 5 and 2. 0 hours respectfully.
$60 Parts + 2 hours Labor (At $60/hour estimated shop rate) = $180. I could see someone charging you as much as this, maybe a little more depending on the shop and what their rates are... a good mechanic is a good mechanic. But I think 2 hours labor is justified. More than this... ?
This is a fairly simple, non-technical procedure. You don't need a NASCAR Pitcrew Technician to do it. Take a few parts off, fix the pin, install a new seal in the cover, and reinstall the parts you just took off (it's more time consuming than anything). The most technical part is torquing the bolts to the correct setting and spacing the crank position sensor away from the vibration dampener about the width of paper clip - there's no rocket science here either... as long as your Tach works then you're position sensor is spaced OK.
Good luck negotiating...