Do you have a different key to try? Your key may be bad.

BTW

Its getting expensive because your "throwing" parts at it. This is very foolish and expensive.

Transponders go bad, Ive replaced a couple- But at this point dont spend a drop of money on it if you dont know exactly what the prombelm is. If that means going to the dealer then so be it. Its not appering to be a "simple " problem