The Complete Works version of Rockman 1 hits the Japanese PlayStation Store tomorrow, August 12th. The download will run you a mere 600 Yen (about $6).
Fortunately, there is no region restriction for PlayStation Store, meaning you can purchase the game even though you don't live in Japan. All you need is a Japanese PSN account (free) and a credit card. A step-by-step guide on setting up a Japanese PSN account here.
UPDATE: Scratch that about credit cards. The JPN PlayStation Store does not accept non-Japanese credit cards. What you can do, however, is purchase a Japanese PlayStation Network card in order to redeem Yen. Instructions on how to find and use a Japanese PSN card, here.