Try an preorder as much as possible as they will run out at the event of some items. Plusa that cuts down on money to carry. When I went to '95 WSJ, I tried to preorder, but b/c of the situation I was in, replacing someone last minute, was unable to. As for spending money, I went to 89 Jambo and Canada with $300. Wish I would have brought more. I recommend always have some cash on hand. I gave the "troop bank" all my money to hold until needed, and when I did need it, the "bank" was on "holiday"

Did you look into the Jambo cash card/ Smart Bracelet?

http://www.bsajamboree.org/SmartBracelet.aspx

You could give him a set amount and then wire more in if he needs it.

Read the fine print. Compare cost of Jamboree card/bracelet with your hometown bank's debit/cash card.

It's not in the fine print, it's in black and white. $15 for something they can't lose and the convenience of it would put my mind at ease.

I visited with my scout about spending monday, the braclet, and the debit card options. He did not want anything to do with the braclet. Said he would use it too often and would not know how much money he was spending. He thought that $50 on a debit card and $50 in cash would be sufficient. I think I may stash a $20 in his bag somewhere as a surprise/bonus (it is a Mom thing!!!!). If he looses the card and/or cash he will go without!
A boy that is old enough to go to Jamboree should be old enough to keep up with his own money and to make decisions how he wants to handle it!

2morrows, that's the way we are speaking with Scoutson. A balance of cash and cashcards.(whatever happened to traveler's checks? they were free from AAA). He will be on Jr. staff, but faces the same "temptations". Did yourScout or you receive the Jamboree catalog? 99% of what is available on site is in that catalog. Preorder some of the souvenir stuff.
The Troop meals and site water jugs will keep your Scout alive, but he may not think that's "living". Ice cream, snacks, "special stuff" will be, by your local standards, expensive. He may need to replace a hat, or buy the poncho he forgot (!). Frankly, $50. for the ten days, plus travel, sightseeing going and return, might be a little low. Budget! Think about your past vacations and such.
Coordinate with Jamboree Troop leadership about meals etc. while traveling...

Traveler's Checks have been been on the decline since 2004. They're way too easy to forge.

In 2005, I acted as the "bank" for our Jambo troop. Some boys had travlers checks which the hotel and Jambo trading Posts would cash. The majority brought money. I had a locking bank bag that was in my posession except when I showered. We recommended $200 per scout. I was carrying close to $7200 at all times. My rules were these. Between breakfast clean up and being relased for the day, the bank was open. It was the only time of the day it was open unless you happened to run across me somewhere out and about. You could withdraw in $5 increments. You could not deposit back. Once you took it out, it was yours. Unless a parent put a daily withdraw limit on their son, he could choose to take all of his money out of the bank. Once in his posession, it was his responsibility. If he lost it, it was gone.

Personally, I couldn't tell you the last time I wrote a check. I use my debit card for everything. I think they are the greatest thing since sliced bread.

Fast forward to 2010 and I am once again acting as the bank for Jambo. My same rules apply. As much as I personally like debit cards, I really, really would discourage anyone but the oldest and most responsible scout from carrying one. They are too easy to lose in that venue and once it is gone.....it is gone. In 2005, we collected all photo ID's once we were inside the Jambo and secured them in the locking bank bag until we left the Jambo grounds and headed to the airport.

I'd send cash if you have a banker or I would send a little cash and use the smart bracelet. It literally has to be cut off your arm. It can't be lost and it is waterproof.....and I don't have to carry $7,000 in cash.