Hi Dianne,
The price for the keyless entry is very high. I have a friend who owns a car stereo store in Scottsdale Az. His number is 480-303-0033. His name is Don. He is a Viper dealer and carries all of the parts you would need. Just tell him that you know me, Dennis Barnes, and he will make you a good deal as well as give you good service. He can also possibly provide the wiring connections color code of your Pinto.
Best regards,
Dennis