The building looks cool for this Halloween event. Is it worth spending the donuts on? Will it give me many benefits for the current event?
Like most seasonal event structures, it probably isn’t worth much to you in the long run unless you really like the way it looks. You will unlock the Torture Coach character as part of the purchase. Yet, again, he is quite halloween specific.
The structure will help you earn the halloween event currency faster. If you are determined to unlock all of the cool stuff that is listed as a reward for this event, purchasing it may be worth it. You should be able to complete the event without purchasing it though so I would not recommend buying it unless you love how it looks as it wont be much use to you once halloween is over. Might be able to spend the donuts on something better.