Ukraine Heavy attack (3 INF, 1 ART, 3 ARM, 2 FIG)
Option 1:
AA Bid to Ukraine ($5 of the bid)
92% Russian win, with an average of 2 ARM, 2 FIG left
Option 2:
INF bid to Ukraine (only $3 of the bid)
86% Russian win, with an average of 2 ARM, 2 FIG
Net result:
For $2 less, I decrease the Russian win percentage by 6% by buying an INF instead of an AA; AND as Germany do not have to risk my FIGs to AA when I want to liberate it on G2.
WIN/WIN/WIN (cheaper/better odds/less future risk) for Germany to NOT buy an AA, but to place an INF instead.