this would make the client experience more user-friendly and reduce the stress on everyone rushing to get images completely finalized before releasing them on the site, or being hit with a big charge for a typo or a change of spec. this proposed model is used by some services which offer similar features for the same reasons stated.
^ This is why I'm hesitating to actually use my PXL to put up an image yet.
The idea of 1-2% for the first one or two changes in a certain time frame, say 3 months seems reasonable, and then increasing costs to prevent misuse. Larger fees for one time services, like making a space changeable, transferring ownership, etc seems straightforward enough.
Have to say, really like where pxl is going.