MST3K is worth paying for.

Netflix has quite a bit of it.

Netflix does have many of them, but not these episodes. Sandy Frank, the genius behind the American re-dubs and re-releases of the Gamera and Godzilla films that MST3k ribbed (which were specifically licensed separate from Toho) pulled some legal bullshit to prevent Rhino or Shout or anyone from putting out the MSTed versions of those movies unless he got paid insane amounts of royalties. Because the MST folks refused to pay, out of spite he just let the rights completely lapse and now Toho controls all of them, making them far to expensive to re-license for putting out the MST versions.