Every four (I think) years we have a Jamboree that is hosted by different States, the cost is uniform no matter where you are so the travel costs for those on the wrong side of the country pay an affordable amount.
My youngest daughter attended one and there were Scouts from all over the country and from different countries, was well organised and a lot of activities for all to participate in so if you didn't want to have a shot at the climbing wall you could go basket weaving or whatever.
I can't remember the cost but it was about $500 for around 8-9 days, that included transport from anywhere in the country so if you lived 5000km away it cost the same as those who lived in the same host town.
It was a great opportunity to meet others from all around the country and overseas, as a Leader I attended for two days as did several others so we all had a chance to experience the event.
The only mishaps were sunburn and dehydration which were quickly address, no bad behaviour and no major accidents just the usual minor cuts and bruises.
Parents could attend at the weekend and it was well attended but as someone pointed out earlier for some it was a baby sitting exercise which was disappointing but that is going to happen anywhere.
Just as an aside, our disgusting little troop decided to give the girls a bit of a wind up, take one clean pair of underwear and smear vegemite inside then lick it off in front of the girls, our boys were really a class act