I'm a used car dealer. I bought an Avalon at auction and learned the hard way about the master key. I always supply two keys to my customer and keep one key myself. Long story short--I only had a valet key and I wasn't about to spend $1500 on a computer and two keys. I found some places that would flash the computer for a lot less, but still way to much to just make some keys. My solution was to zip-tie the valet chip key to the ignition cylinder under the dash, then just use non-chip copies of the key to start the car. The car thinks the non-chip keys are chip keys because it senses the key that is zip-tied to the ignition. My customer doesn't even know it's there. You have to fiddle with the location/position of the chip key to make it work, but it will work when it's in the right spot.
