I normally wont buy game changers for this very reason. Once event is done they usually drop so much they are worthless and sit on my bench this late in the year.
You will find people who do want to ride the free wave and collect all the rewards the can from a club who spends money while they dont...it does happen
I will never figure out CVC. Sometimes i score better manually and then there are times i will score a lot better on auto. I do feel the boost are worthless and do not help at all.