$150 for head bolts seem high, but then again I've never bought any, especially for a diesel. Seems to me they are just bolts of the right size and length.
I'll be curious what is said here.
I am by no means an expert, but I believe that head bolts on engines are designed to stretch a certain amount with the proper torque, and are a single use item. I would go to a good auto parts store or a trusted auto mechanic and get their opinion.
It's little sister, the 1710, uses studs and bolts for the head.
While 'torque to yield' head bolts are used on some motors, I don't believe this is one of them. Their use is more within the last decade.
The 1710 service manual describes the normal step torque and cross pattern technique for reattaching the head, not the process for 'torque to yield'. Consequently, the bolts and studs can be reused unless there is some thread damage.