It will be quite a shock for me to see those films from 40yrs ago, when I was a youngster...I havent seen a lot of those films in many years, so it will be fun, I suspect... Forget the shock of seeing them - think about the sticker shock after having them all converted to VCR. Having them done properly is not an inexpensive venture, so you might want to do them one at a time.
I suspected it would cost a good deal...I think your suggestion is a wise one...take one spool of film in at a time...spread the cost over time...