and for an alarm movement?
no thanks.
just look harder and you may still find one selling for a reasonable price.
even in HK I've seen a non-alarm 240 stem-wound movement in an almost nos condition selling for just $1000; they are out there.
think of it as an NOS movement then you have nothing to worry about.
vintage pam doesn't necessarily have to look "vintage"; some gen ones are very well preserved and still look quite new.
also, your 3601 is probably already 40-50 years old, and still looks brand new. i.e. a legit vintage movement can look mint.
You must have looked like a tourist to the seller.
To be honest, a local can buy this watch for USD50 max. Even at USD50, the sellers make a decent profit.