This haphazard method won't get accurate data, but it should provide an inkling...
The only use we have for Cores is Limit Breaking, yes?
3x T1 for R
3x T1 for SR 3*
3x T1 3x T2 for SR 4*
5x T1 3x T2 for SSR 3*
5x T1 8x T2 for SSR 4*
Having added the spent Cores to what I have in my inventory gets me:
Fire: 128 T1 34 T2
Water: 166 T1 81 T2
Wind: 72 T1 45 T2
Thunder: 240 T1 85 T2
Dark: 116 T1 40 T2
Light: 122 T1 38 T2
Or if you lump them all together: 844 T1 323 T2
And this is with almost purely Experts.
Is there anyone who'd have similar data from purely Standard side?