My apologies, 50k-ish was my assumption, based upon that being the approx amount on several previous occasions. Again, I assume they gave us 8 runes? as previously.
I'm also convinced the 'rune-ometer' is not dependent upon player input, but rather set on a timer so as to complete just before the end of the event, but sometimes goes bit loony. - Did you notice the total amount this time was still below 15m an hour or so before the end, then 'magically' climbed to 400m just in time!!! - They did though definitely let it 'fail' on one occasion, when the Sandcastle was not awarded. They then awarded that as a bonus prize mor recently!