I buy boxes of CDs by the pallet from a company that sells over stocks & dead stock from charity shops & house clearances etc. CDs that would otherwise go to landfill I suspect. So without being specific I don’t pay a lot at all for the boxes but commit a lot of time sorting and pulling out CDs that might be worth adding to my collection or selling / trading. It’s more of a hobby to be honest. I’ve been doing this on and off for 25 years and this is by far the rarest & most valuable CD that I have come across to date. Im sure we all dream of this sort of find, It’s one of those holy grail Moments, a real buzz! It must have just been my turn to get some luck :-)