[JTM45]

As anyone who understands betting will know, all odds are are an indication of who people are putting money on and at this point very few people are going to be putting money on the pretty much certain winner, Ashleigh!
So people are taking an outside chance on Helen because if, by some miracle, she was to win then they'll have a very good payout (because the chances of it actually happening are so slim!).

For a real indication of who's going to win you need to be looking at things like the Tellmix Poll where Ashleigh's currently at 43% of the vote with Helen just a bit behind at 10% of the vote.