Carpediem42

Hello, Needing advice. My 2001 Prius is displaying the triangle with ! and the car outline with !. I noticed nothing different while driving it. It sat idle in my driveway for 2 weeks and then when I tried to start it, it was dead, just whined. I used my trickle charger overnight and then it started fine, I drove it around the block several times, again it seemed normal. Had it towed to repair shop and today was told the Main battery, main computer and power steering motor are shot and it will cost $7300 to fix it. Really? What should I do? It has 170k+ miles on it and has been a great and steady car. I've done all the normal maintenance. 12v battery replaced in 07. The day the symbols showed up we had a very windy rain storm with horizontal rain. Advice? Please and thank you!!