Exporting specific page + last page automation

You can get page 1,100,2,100 etc. in consecutive pages in a PDF by exporting the page range

1,100,2,100,3,100,4,100,5,100,6,100,7,100,8,100,9,100,10,100,11,100,12,100,13,100,14,100,15,100,16,100,17,100,18,100,19,100,20,100,21,100,22,100,23,100,24,100,25,100,26,100,27,100,28,100,29,100,30,100,31,100,32,100,33,100,34,100,35,100,36,100,37,100,38,100,39,100,40,100,41,100,42,100,43,100,44,100,45,100,46,100,47,100,48,100,49,100,50,100,51,100,52,100,53,100,54,100,55,100,56,100,57,100,58,100,59,100,60,100,61,100,62,100,63,100,64,100,65,100,66,100,67,100,68,100,69,100,70,100,71,100,72,100,73,100,74,100,75,100,76,100,77,100,78,100,79,100,80,100,81,100,82,100,83,100,84,100,85,100,86,100,87,100,88,100,89,100,90,100,91,100,92,100,93,100,94,100,95,100,96,100,97,100,98,100,99-100,100,100

(which I did very easily with Excel)

When you get your PDF you will have

1

100

2

100

3

100

etc.

Then use Acrobat and go to Organise Pages - and find the Split Option

Split the document by 2 - which will give you 

1,100

2,100

3,100

as separate PDFs

You might need to play about with the naming conventions to get something that works for you

or run a batch rename sort them out.

But should get you there 99%