I actually tried this today, in three chunks of 30 minutes.
With this deck:
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mark of
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I managed to play only 11 games (i played very slow in the last chunk), here are the results:
hermess - loss
miracle - win, +120
seism - loss
seism - win, +58 (probably a mistake in the end costed me the mastery)
scorpio - loss (I usually beat scorpio with this deck)
destiny - win, +120
rainbow - loss (I played a few turns, but it is not even worth it vs rainbow)
chaos lord - win, +120
divine glory - win, +57 (I usually lose to divine glory with this deck)
seism - win, +120
seism - win, +120
total 715 - 120 = 595 coins
plus 7*3 = 21 spins