Don't know if you got this email from 1C Games Studios (40% off Battle of Moscow promo code).
But if so, I just both Battle of Moscow at 40% off the 49.95$ for the standard edition... that's around 25$ USD for all the planes and the missions.
I did also downloaded the latest version of PWCG for BOS... I will try it out this week for sure!
ps@ for the 40% off, works for steam or none steam games.