Pricing of Premiums

Hello, I just stumbled upon personal discount for SU-122P and did actually wonder (10 percent ... so maybe next time), what would cause somebody to buy vehicle, which in comparison to SU-100 (same hull/look) has most attributes slightly worse, sits at the same BR 6.3, but costs over 6000 GE (SU-100 is free of course). SU-100 ammo 240 mm APCBC vs. SU-122P 230 mm APCBC, SU-100 reload time 13.7 s s. SU-122P 21.7 s. Otherwise the SU-122P has: - worse gun depression (1 percent ...), - worse turret rotation speed (negligible ...), - worse inclination, - less HP, slightly more weight. I just had a good laugh, but I'm a collector, so better discount like 75 percent and I'll buy it, just to have it. It's not the only Premium with ridiculous pricing or weird BR (the same situation was with KV-122 vs IS-2 - free better vehicle with less BR vs GE paid worse vehicle with higher BR), so I wonder, do you guys think, that the Gaijin team actually looses insight? In the reality of the game? I've heard many times things like ... according to our statistics this or that is doing well, even if that's not true. Does person, who would buy the SU-122P for the full price, exist or did some of you buy it for that amount of GE? Or any other similar vehicle? And why? Not a ground forces discussion, dear mods, just pricing/collecting things discussion. Thanks.