He is a friend who knows you are into comics, so you get preferential treatment, and he asked you to pay half of what it is worth when you found a $100 book in a pile...and you gave him $1.50...?
Seems a bit dishonest, IMO. Sounds like you are proud of the fact that you took advantage of him. Am I missing something here?
Half Price Books would have put the book out for sale for a dollar.
Not necessarily. Most HPB stores have a locked box in the comics section for more "valuable" comics. As to who or what determines what goes in there, and at what price, I am not sure.
For instance, the one by me has Wolverine Minis 2-4 for about $25 each; some old Crime-related comics; and a Secret Wars #8 that I picked for $10 with my credit.
There was also another post around the boards with a store stocking an ASM #50 for $300.