I thought that was a very interesting proposal, thanks for the great suggestion Erick!
Our bandwidth costs are already up to nearly 1 terabyte a month serving up HD card art and rising all the time, which is a major reason why we have not implemented an option to download all of the HD art offline. Each download of the entire collection of HD art would probably consume approximately 2-3 gb of bandwidth as well, not to mention the same amount of space on your device.
Collecting a nominal fee for allowing the offline caching of the entire HD card art collection is an interesting proposal to help us offset the bandwidth costs. Does a $2.99 fee make sense for this option? The fee would be to allow multiple downloads of the card art in case you run Decked Builder on multiple devices. It would also be for up to a year, to allow you to download HD art for new sets as well. Write in to firstname.lastname@example.org or post below to let us know your opinion. Thanks!