Ebay. I’ve been selling lots of worthless comics for about $1 each in lots of 25, and I had a number of books worth something too (thank you, Mr. McFarlane!). I found it weird that they are worth something because no comic from the 1980’s is rare, but in 50 auctions I pulled in over $1500, and not a single book of mine was CGC rated although most were in excellent condition.
Get some boards and some bags and start taking photographs. The comics will sell, eventually.
Ta have, as Little Red Riding Hood said. I sold Secret Wars #8 for $8.50 and the ASM debut of Spider-Man’s black suit (The Most Profitable Costume In The World) for $18.50. I don’t know if that’s top dollar, but I paid less than $5 for the pair, already as back-issues, when I was 15. That’s a pretty good ROI for some newsprint I had sitting in a box. But I didn’t really want to part with them because they were just too darn pretty.
Amazing Spider-Man #238 alone (first appearance of the Hobgoblin) should get him $60-$120 depending on condition. If he has that of course.
Thor #337 (First Beta Ray Bill) around $15-20
I’d have to actually see the collection to get a grasp on what isn’t and is valuable.
As others have said, he should just hang onto the collection.
This is where I listed everything a few years ago but no longer have the login info or the email account under which I registered.
The price it gave me may have been $2k, not $4k. I don’t recall clearly, but I took it with a grain of salt.
I don’t have it handy, but the highest value single issue in the bunch was one of the Spider-Man titles.
After that, it was the Punisher mini-series, IIRC.
#252? First appearance of the black costume? I got one of them.
Secret Wars is valuable? I’ve still got all 12 bagged and boarded. I kept those because i liked te story. Particularly the cover where Hulk is holding up the mountain. Also kept Infinity War. First issue cover is cool. And I liked the story.