@Plaz - A sealed copy of mule came up once in the last 5 years, if I recall it sold for $300-350 dollars.
Did anybody message Wayne on ebay? He will likely tell you if you ask. Generally most of the stuff he sells is legit/original. He now has a license to legally produce jiffydos roms from Jim Brain.
Not true actually. Sealed copies of MULE have popped up from time to time in the past two years on Ebay and go for between $150 and $200. There have been one or two in the $300 or so range, but generally that's when a bidding war breaks out between two collectors that have to have it right now. The Atari 800 version is even more in demand as it is the one Dan Bunten considered to be the most similar to his original concept and it allows for four joysticks to be used at once.
