I tried them on a client project today, and they found some (minor) form post issues. the scan used roughly 1.5hr, which results in "incurred cost" of $4.75 (for their cloud ressources needed), and they suggest a 5x "gratitude" factor which I gladly paid.

So they tell you how much they spent on cloud resources and even suggest a gratitude factor? That is actually a great way of getting paid (enough) even if you do not enforce any fixed pricing, cool! :)

Very interesting in deed. There is a auto driver in India (a taxi like vehicle) who uses the same pricing model for his services - http://www.thebetterindia.com/4813/tbi-heroes-ahmedabad-no-r...

Nice to know about such things :-)

I like the price but they found nothing, honestly, and we're not very nice when I emailed them for support.

Just wanted to point out the hilarity of your typo: "we're not very nice when..." vs "were not very nice when..." completely reversed what you meant to say ;P.