I'd rather share my art/files for free (indeed, I already have) than start worry about charging. If I ever did anything for $$$, it would be on commission. My $0.02.
Thank you for the opportunity to clarify my statement. It would be something on the lines of the donate button on
http://www.koenigs.dk/mame/eng/ but with the sliding scale. I don't get the impression he is charging the single user at all, just offering an avenue for donations *just in case* someone is motivated.
I don't mean to charge others. I'll use the recent DK plans as an example. They are coming together nicely aren't they?
So 2 dudes are geographically separated working on compiling these sheets of measurements. Putting in a few hours overnight to get it right. The closest nintendo cab to me is over an hour away at a hotel. Its in odd place to take measurements; not at the end.
I'm not talking a large amount, but a buck or two to say thanks; a
token of appreciation. If they didn't care to make use of it, they could donate it to the site for hosting.
In this case, ideally I'd enjoy the plans to have a table of contents, parts list, board count to include dimensions as well as other parts like hinges, marquee retainers and of course the arcade parts as well as the measurements they've included.
It's a novel idea, not something I'm going to guilt, or push others to do.