Premium Ammo Cost

 Tzimon, on 22 March 2011 - 10:46 PM, said: Since I have over 9k gold and only a few weeks of beta left, I decided to start using premium ammo for most of my tanks. I think I've discovered a discrepancy in gold cost for premium ammo.
Tier 8 Heavy
105mm Gun T5E1 ROF: 5-7.23 r/m (T32) 12g per shell
122mm BL-9 ROF: 5.17 r/m (IS-3) 12g per shell
10.5cm KwK 46 L/66 ROF: 6.06-6.32 r/m (KT) 10g per shell
Tier 9 Heavy
120mm Gun T53 ROF: 6.55 r/m (T-34) 12g per shell
130mm S-70 ROF: 4.44-5 r/m (IS-4/IS-7) 10g per shell
12.8cm KwK 44 L/55 ROF: 4.64-4.69 r/m (Ausf B/Maus) 10g per shell
Tier 10 Heavy
155mm Gun T7 ROF: 3.64 r/m (T-30) 12g per shell
130mm S-70 ROF: 4.44-5 r/m (IS-4/IS-7) 10g per shell
12.8cm KwK 44 L/55 ROF: 4.64-4.69 r/m (Ausf B/Maus) 10g per shell
Based on list cost above I have a few questions for the Devs.
#1 Why does it cost more gold to buy ammo for 122mm BL-9 (IS-3) than for 130mm S-70 (IS-4/IS-7)?
#2 Why does it cost more gold to buy ammo for 122mm BL-9 (IS-3) and 105mm Gun T5E1 (T32) than for any other Tier 8-10 Tank (except Americans)?
#3 Why does it cost more gold to buy ammo for 120mm Gun T53 (T-34) and 155mm Gun T7 (T-30) than for 130mm S-70 (IS-4/IS-7) and 12.8cm KwK 44 L/55 (Ausf B/Maus)
(mod note: I don't have 50 posts yet so couldn't post this in the proper "questions" forum, feel free to move it if you wish. thx)
edit: added ROF so that the data is more complete
moved to questions section