Mostly u are not able to negotiate on price, but hey, why don't u give it a try. If u succeed, u save money! I know some ppl negotiated on the fixed site costs by using other company's free quote, and they succeeded. For example, Burbank quotes u 8000 AUD for fixed site costs, and u got Simonds or Metricon free site costs' quotes previously which are 2000 lower. Using this as a bargaining tool to ask them redo the fixed site costs, and Burbank may lower the price. However, for the colour selection, I don't think you are able to bargain. Cuz they got a specific department calculating the price for each item for different houses. The colour selection people just give your advice on colour/style. The prices are calculated by the calculation department and they communicate via computer so you can get the price within the colour selection day.
About the time length, I'd say 1 year. Typically in Burbank, pre-consulting/pre-contract (fixed site costs)------contract singing------land titled------soil test------colour selection------drawing------construction------move in. Drawing would take u months to be done, I know someone wait about 5 months to make the drawings to be done correctly. Be prepared and push your admin frequently.