Additional question: ignition switch on 2005 Toyota Camry

I asked this question the other day and got a reply, but I have an additional question
Q: I got into my car and as I started the engine, the check engine light, the brake light and the ABS light came on. The power windows were not working and the AC didn't work either. I had all fuses checked, but nothing was wrong.

A: This could be a symptom of an ignition switch issue. When the condition happens wiggle the key to see if anything changes. If the contacts in the electronic part of the switch go bad this can happen. You might even be able to make the symptom happen by moving the key up & down.

My question is, do I have to replace the ignition coil to make it go away? Sometimes it works fine, but yesterday I couldn't even see how fast I was going.
And how much would that cost me?

Asked by for the 2005 Toyota Camry
Intermittent ignition coil failure can bring on a Check Engine light for sure and I have replaced a few coils on Camrys but the usual Check Engine light related problems are usually Oxygen sensor heater circuit of sensor performance problems, evaporative emission problems or air flow meter related issues so checking the source of the Check Engine light problem is important to figure out. I haven't sen much ignition switch electrical portion failure (Honda had a lot of problems). The windows are on a different circuit. Get someone to sit in the drivers seat and watch the lights on the dash while you wiggle electrical harnesses with the engine running see if any fuse blows or lights go out, windows start to operate ect....
If you are mechanically minded and are comfortable reading wiring diagrams there is a company that independent auto repair shops "buy" their information from that offer a very reasonable service to do it yourselvers. You get a one year subscription to year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... great quality information same as the professionals have ,much better than generic workshop manuals from parts stores, much cheaper than the factory manual.