Regarding scoring points, in addition to the previously mentioned recommendations, I can say that there is a random factor when a "creature week" occurs, from which cheap ghosts are obtained. In my record save, this happened in the last week, but it was not possible to gain a significant advantage.
I agree with you that scoring more than 700 seems unrealistic, but it is possible to add to my result. Therefore, I was interested in specific numbers.
Sincerely, ass1952.