In many countries, electricity generation stations are interconnected with a system called power grid which allows the electricity generated in one place to be sent to users in another place. Electric dispatching center is able to reroute electricity to where it is needed. Any generation company (GenCo) has the right to join the market if they want in order that they are able to compete with each other to generate electricity for profit. Thus, they need to make decisions of which power required areas are worth choosing before sealed bid-one type of electrical bidding. However, they have uncertain information of rivals' cost. This paper proposes a semi-automatic pricing mechanism for the decision support for electricity generation companies to make bidding decisions which maximizes their profit in multi-area power grid system, and to evaluate effect of information uncertainty for decision making.