after having a look on youtube, i found
a video that i think is pretty informative in the context of my current problem.
if a lifter fails or gets stuck, it can damage the corresponding lobe on the camshaft, which requires replacing the camshaft. the video works out the cost of the replacement parts and the labor required, as quoted by a dealership, as roughly 2k in parts and 5k in labor (30 hrs). i also see that it is common for dealerships to advise full engine replacement, presumably to avoid customers being angry that a partial fix did not work and to maximize profit for their shop.
the video is only 1 year old, and the comments are rich with content from people who have had the same problem. i see several accounts of similar quotes to what i got to replace the engine, 12-14k.