Out of curiosity I checked my 100+ neighbors to see how they are doing building the pond and as far as I can judge it probably nobody will be able to upgrade the pond to lvl 10. Let alone getting the frog as a price. Not that my neighbors are lazy cause most of them completed the previous event. I think S8 completely failed at the event or that we have a taste about the future of this game: only for the happy few who can afford spending a bucket of gems. Next event we will prob know the answer.