Some vaulted prime frames are not worth the expensive price or am I missing something? Should I just invest in their normal version?

Take Mirage Prime for example. For 85 plat on the market, I'm getting:

+ Extra 100 Shields and 80 armor

+ Extra 2 Polarities

I'm still new (MR 10) so maybe there is some advantage I'm not seeing. All I know is that a forma bundle cost way less than 85 plat and that extra shield and armor will matter less and less as I progres further. In this situation, should I just invest in normal Mirage and wait until the prime come back via resurgence?