How much does it cost to replace the body control module?

What is your question?

It seems like my car does the "disco" thing whenever the temperature outside is 70 degrees or higher. The radio goes on and off, the windows wont go up or down, the horn beeps on its own, the auto lights flash on and off, the battery light comes on along with my check engine light. Ive had the battery replaced twice, and now the problem is so bad that even when the car is off the door locks and unlocks itself. I have to manually disconnect the battery cables to make it stop. Sometimes the problem is so bad the the security light comes on and nothing works at all and again the only way to get them to work is to disconnect the positive and negative from the battery. After doing some research it sounds like it i may need to replace the bcm(body control module). Please Help, Im ready to pull my hair out.