You can go higher than that.
Use 19704 to receive 700 units
Anyway, I have generated the list of total units to select to obtain units to the nearest 100.
Elect...to get
2837 100
5623 200
8460 300
11245 400
14082 500
16867 600
19704 700
22489 800
28112 1000
30947 1100
33734 1200
36569 1300
39356 1400
42190 1500
44978 1600
47811 1700
50601 1800
53432 1900
56223 2000
Please verify these numbers and use at your own risk!
This made for an interesting inverse problem..... though I am more inclined to use brute force to arrive at these numbers numerically rather than analytically .....