Some information on the length that Balto 2 required, and the sales it got.
Information taken from the 'Animation World Magazine' website
According to the article, in October of 2004, Balto II had generated $6.14 millions on rents. The Land Before Time 10 only managed to bring in $2.32 millions. In total, Balto 2 sold $22.45 millions, compared to $24.51 millions for LBT 10.
It also says that the general cost of such a DTV sequel is $5 million to $15 million. But the most interesting information here comes from the production length. The article says:
'For traditionally animated, 2D features like Charlotte’s Web 2: Wilbur’s Great Adventure (produced by Nickelodeon and distributed by Paramount), or Balto 2: Wolf Quest and The Land Before Time: The Great Longneck Migration (produced and distributed by Universal Studios), the general production cost is $5 million to $15 million, with an approximate schedule of 70 weeks (38 weeks for preproduction, 36 weeks for production, and nine weeks for post-production). '