You'll need to speak with an engineer to answer your question. The costs on septic systems vary widely.The size of the septic system is determined by the # of bedrooms.The type of septic system is determined by the water table and other factors. If the water table is high, the system may need to be raised. If there are any wetlands on the property, that is also a factor that affects the placement. If a system isn't gravity fed, a pump chamber may need to be added. A perc test needs to be done to determine the water table. An engineer will design a system for the particular property and its conditions. Once you have a system designed (and approved by the town) an installer can give you an estimate.

Michelle-
The size of the septic system is usually based on number of bathrooms and size of home and what is required by local codes, not the type of house. Do you need the whole system replaced or are their just parts that need to be replaced? Can you get a copy of the septic inspection? I would recommend calling a well/septic company in your area and they should be able to give you a ballpark figure or maybe they would come out and provide you with a free quote.