Regarding pricing: We talked about the wording internally. It was decided that different people pay different stripe fees (eg volume discounts) and stripe may change their fees in the future w/o notice, so it's best to simply state what we charge. I've added a link to Stripe's pricing page to make things a little more clear.

Regarding the demo: we're planning on adding one to the home page. Until then I added the button to my blog: http://sam.odio.com/2012/10/31/buy-me-beer/