If you ever find this for a decent price,get it for the Son of Godzilla and the other older Mechagodzilla film:
Godzilla DVD Collection - 50th Anniversary (Columbia Tri-Star)
- Godzilla: Tokyo S.O.S. ( ゴジラ×モスラ×メカゴジラ 東京SOS ) ( Gojira tai Mosura tai Mekagojira: Tokyo S.O.S. ) (2003)
- Son of Godzilla ( 怪獣島の決戦 ゴジラの息子 ) ( Kaijuto no kessen: Gojira no musuko ) (1967)
- Godzilla vs. Mechagodzilla ( ゴジラ対メカゴジラ ) ( Gojira tai Mekagojira ) ( Godzilla vs. The Cosmic Monster ) (1974)
( Godzilla vs. The Bionic Monster )
or these:
Son of Godzilla (1967) (Columbia Tri-Star)
Godzilla vs. Mechagodzilla (1974) (Columbia Tri-Star)
I think there's also Aussie dvd's of these?