My son has friends at several corps and shared some numbers with me a few weeks ago. I also have close friends who like me are supporting a member this summer so this topic came up as well. The highest fees, from what I gathered so far are below. I'm leaving corp names out, but really isn't that hard to get the info.
These fees do not include what it costs to fly to camps, book hotels if the corp does not provide housing at camps, or spending money while on our. That can add another $2,000 to the tab for one season. This is a very expensive activity.
$6000, $6,500, $6,900, $7,000, $7,500