Looking for appraisal of kulstar, balla, and obex rivens

[Nefrax]

So I have [kulstar conci-cronibin] 

An unrolled riven that provides the stats;

+7.7% ammo max (+69.3 at max rank?) 

+8.9% projectile speed (+80.1% at max rank?) 

+7.3% fire rate (+65.7% at max rank?) 

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[Balla decitio] unrolled

+11.8% electricity (+106.2% at max rank?)

+13.2% status duration (+118.8% at max rank?) 

-4.9% critical chance (-44.1% at max rank?) 

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[obex igni-magnatis] unrolled

+11.0% impact (+99% at max rank?)

+8.4% heat (+75.6% at max rank?) 

+7.7% critical damage (+69.3% at max rank?) 

 

What would these go for? I don't wanna get ripped off is all