How many entries do I want ?
If a number of ancestors are already included in the Index and you want to add just one more, then you may need just the one entry.
If you wish to include the names of a person plus 2 parents and 4 grandparents, then that is 1+2+4=7 entries. If you wish to include the names of parents, grandparents, great-grandparents, uncles, aunts, great uncles, great aunts etcetera then you may want quite a few.
Acquiring larger numbers at one time is better value but, if you have reservations, start small to let yourself be satisfied that you are getting what you are paying for.
If you are uncertain, then it is suggested that ten (10) entries is a good starting number. After including the names and information for 10 people in the Index, you will have a better view of whether you need more and how many more.