Time to start work on a budget if you have not already. Estimates will do.
The approach to funding trips to a jamboree varies considerably from Troop to Troop. Some parents opt to fund the cost themselves where they find they do not have the time to commit to fundraising.
Other Troops choose to fundraise, nearly always achieve the goal and while doing so, the parents, leaders and Scouts tend to become friends and more supportive of the Troop. This also provides a great recruitment opportunity and encourages retention in the Troop.
The Time To Plan document contains more details and examples.