I would suggest, try Skilled Independent 189 or Skilled Nominated 190 and get a migrant visa. 457 might also cost the same or more, and if your future employer wants to factor in the expense into your salary, then it's as if you are paying for it anyway. After you get your migrant visa sorted out, then take a trip to Australia. Contact companies and see if you can line up some interviews during that travel.
I don't know who suggested you that the only option you have is 457, but clearly that is not the only option. 457 is not anyway cheaper than 189 or 190. Plus you have to get one of these anyway even if you come over with a 457.
Don't try attend interviews on a travel visa though. The immigration officials don't like you looking for a job when you are on a travel visa. Probably see if you can come on a business visa for such a trip. If you are serious about migrating, then I would suggest you come with a migrant visa. Doors are actually quite wide open. Nearly 47,000 such visas were issued for Employer sponsored and nearly 74,000 visas were used for general skilled migration for the year 2012-2013. So there is almost twice the number of people migrating to Australia through general skilled migration.