I'm the author of the piece. I think the best clues are that the mystery hiker told people he was from Louisiana, and that he worked in the tech industry in NY. I suspect someone here might recognize him. I'm reachable at nxthompson at protonmail.
I don't have numbers from you, just that bit of context and some supporting quotes off the record.
Qualification: I tech-consult producers and writers on screenplays.
Here is one agency in particular: https://www.epicdigital.com/
https://www.themanual.com/outdoors/best-down-jackets-2017/
(Second one down.)
My cousin mailed fifty bucks and some spit in an envelope on Monday and Wednesday I get an email from 23andMe saying "Hey! We think this is your cousin's spit!". And neither of us is missing!
Also, even if full sequencing were needed, we're not even talking de novo sequencing, full sequencing is routine daily work nowadays.
1. collecting a DNA sample from a corpse is more difficult than having someone spit in a tube and drop it in the mail. It takes tools and a specialist
2. they want to compare with lots of different databases. Most GEDMatch data comes from genotyping arrays, that look at ~500k variants on the genome. However, different companies use different sets of single-nucleotide variants. Meanwhile, law enforcement databases look at microsatellites, which can't be assayed easily with an array. Sequencing someone to be able to use all the different databases would be on the order of a thousand dollars
3. The genetic testing companies do things in bulk. Your cousin's spit was run though the various steps (like PCR) with 100s of other samples. Doing it for a single sample is going to be more expensive
https://www.youtube.com/c/LEMMiNO/videos
Maybe it could be a good basis for a video