Hmmm, I just re-read your original post. It sounds like you are trying to use the $5 to supplement the essentials - not to purchase the essentials themselves.

If that is the case, then yes, I think $5/Scout can go a long way.

You can buy real cheap - and fairly decent - whistles at orientaltrading.com (search using IN-20/45) for $2.99/dozen (plus shipping).

Plastic bags are cheap. If you contact your local highway department and tell them this is for Scouts they may give you a bunch of the large orange bags for free.

You can buy cord fairly cheap, depending on your source.

Signal mirrors will cost more, but go to your local dollar store and see if they have some small plastic mirrors. Its easy enough to use a mirror without the targeting sight (see Doug's ETS site for a description). http://www.enasco.com/product/9727797 has them for 75 cents each.