Another idea is to have a "set your own price" w/wo a minimum price, like with Bandcamp, where the download is like a post-donation gift. Also, once paid, the p

Another idea is to have a "set your own price" w/wo a minimum price, like with Bandcamp, where the download is like a post-donation gift. Also, once paid, the purchaser may want to be able to leave an email address or message to get further discounts in the future from the artist as VIP fans.