hey adam,
If they say it costs $700 its bullshit, as the MY94-96 and the Bugeye onwards use a single piece AFM which costs $700, and the MY97-00 uses a 2 piece which costs around the $300-350. I was told this by the parts sales guy at ozzy park when i was ordering a new AFM for my MY94!
I'd say one of your many sensors have gone!
Your car just doesnt want you to go hey