My 2002 chevy venture uses chipped keys. About 90 bucks from the dealer, must prove ownership, identity, title to vehicle, a whole list of security stuff for a old vehicle

Wallmart sells the chipped key for 35 bucks. depending on the store.

you tube has a video of how to bypass the system. Basically get a sensor, attach a chipped key permantely to the sensor. Add a relay so when you turn the key, a non chipped regular key trips the relay, activates the chipped key and sensor....