Atari 5200 Boulder Dash II: Rockford's Revenge by First Star Software was recently released by Atari2600.com. BD2 was produced in four bold colors (Black, Red, yellow, and Pink)each in a quantity of only 25 serialized examples.
A single example of the Black version remains available, while fewer then five Red and greater quantites of Yellow and Pink remain.
Additional information including a walk-through of the first cave can be found on the Atari2600.com News page http://www.atari2600.com//news.php.
Price $40.00ea + S/H.
JC
Atari2600.com