Interesting perspective.
Here is a theory though:
BAF currently operates the Mi-17 transport helicopter with armaments attached. That helicopter is completely different from Mi-28NE or even the older Mi-35 Hind. By that logic, your Air Force also operates the AW-139 tactical helicopter which is essentially the same company Leonardo that designed the A/T-129 (T being the custom Turkish version).
Mi-28 is a heavy gunship and will incur a higher operating cost per hour compared to the T-129 which is a lighter and more agile option. While initial costs will be high, but operationally Western helicopters are cheaper to operate and have a better operational readiness.
What do you think?