Mitsubishi Rekeying Problem

I recently purchased an older model Mitsubishi Montero for my daughter.
I need to get key made for the ignition and door locks. There were
none available. I was told that if I took the passenger side door
lock, with it's serial number and the vehicle VIN, a competant
locksmith could get the codes and cut a key. We took this information
to the local shop and the lady took the serial number but not the VIN
and got a code from the internet. The resulting key works on the door
lock, but not the ignition. She said she could "impression" a key for
a lot of money, or I could buy a new cylinder from the auto supply for
about $60.00.
This shop owner is a new locksmith and I don't have a lot of confidence
in her and there isn't another option in my small town.
Any ideas??
Thanks