I thought you'd do this for free, as a favour
When I left my last large employer I was effectively last man standing with the knowledge of certain technologies, including having a database of over 3,000 technical references relating to the modelling of things that might burn or go bang. I had five filing cabinets of paper which I had been told to remove from the building otherwise they were going to be shredded. These filing cabinets & two bookshelves were living in the back of my double garage. This was the days before fast scanners so much was still paper although I had begun scanning the important stuff into PDF format.
About 7 or 8 years after leaving the big company one of my former line managers rang me up requesting a particular (important and obscure) reference which he was having great trouble in finding. A quick look on my personal (Lotus Notes) database showed that I had a copy of the reference but it hadn't been scanned in.
"Oh, good can you just send me a copy".
Yes, but there will be a charge
"I thought you would do it for free, as a favour [for me]".
To get you a copy I will need to go out to my garage, root through the filing cabinets, then either scan the file in or else photocopy it for you and post it. It will cost you £150 for my time to do this.
"Oh, can't you just do it this once?"
No, your company hasn't given my new small company (I was a director) any work in the past 5+ years. if you had been giving us regular work, or else you had an upcoming job for us, then yes, I'd probably do it either for free or else bung a few quid on the next job. As it is, if you want it then you can pay.
Conversation terminated with a very grumpy former line manager (for whom I had no great love in the first place).