I have received several different notes pertaining to the Scout "event" covers. The notes question two areas primarily: cost and "official" status.
First let's keep in mind that the event covers are usually a fund raising item. As such, prices vary widely (from 35 cents to 3-4 dollars each). The only measure that can be applied legitimately is: What are you willing to pay? The covers, for the most part, will not realize any real value when put up for sale some years from now unless you find just the right buyer.
As far as official status is concerned, who is to say? The event covers may be created by a sponsoring group and those would probably be called "official."
Many dealers send blank covers for first day cancellation and then apply rubber stamp or photographic cachets later. This now raises the question: What are you collecting, the cachets, the stamps or the cancellations?
For any event where there is a special cancellation used, you will find many cachets are forwarded to the postmaster to receive the cancellation. As a result, there will be hundreds of covers, both cacheted and uncacheted, in circulation. Some of the covers will be sold, many will be traded, and the majority will end up in some collection that will be sold in the years to come.
Buy the event covers for what they are and enjoy them for what they are.