They finally made an event you cannot finish within the current time frame using the current event speed.

At max click rate, you can get 890 event points with 10 starfish. I used 14 more starfish and got the same rate, for a total of 24 starfish and 2136 points. So the math is 898 gems needed for 80,000 event points. The ~9 days of the event is 2 starfish per hour. That is only 432 star fish that you can get from chests. I also doubt they'll be giving away 500 starfish in the next weekend competition. So, unless there is one heck of a speedup, towards the end of the event, you can't complete the BJ event with considerable investment with gems.

Assuming they do add some sort of speedup towards the end, I'd hold on to my starfish and make them count as much as possible. Using them before any sort of speed up bonus will be a huge waste, and I've already used 24, and I started the event late this time, ~9pm, EST last night.