Hi, does anyone sell coins that are unfunded - pref DIY so I can print the private key myself and know I am the only one that sees it. I've seen one but wondering how many are out there. Most that I see already have a specific bitcoin amount on them. I'm looking for something that is more like a physical wallet made out of a coin so I can put any amount on it without having to match the amount on the coin (i know this isn't actually required). Thanks