Guides are the least expensive part. I think they are about $15/ea for OE last time I did them on an M117. I have an IWIS chain in mine, it has seen 6000rpm many times over the years (or wherever the full throttle shift RPM is located). Labor here is $100/hour...I guess I could see a full day to do the job. Maybe.
I am not seeing the camshaft oiler retainer clips, seems odd for a near $2000 bill. 1161800184 Same for valve cover bolt crush washers. Also, I would hope cam timing is checked and adjusted with woodruff keys if you do a new chain. I swear I used three of them to make my cams 0/0, but forget my offset on my application.
$2k is also half way to a valve job on an M117, which they all seem to need once past 100k. Also odd is that the intake manifold reseal is not recommended by the shop due to the age of your vehicle.
IMO, swap the guides, cam lube clips, cover gaskets, and get on with life. I always see failed guides in the junkyards, thus bent valves. Never a chain that has exited through the motor. Not saying it has not happened, just I do not see dual row chain V8 cars in the yards due to that.
If you are handy, you could do the guides yourself for probably no more than $150... including rail extractor tool.
PS - any pictures of the R107 of yours?
