The biggest scam with these international conventions is the free tickets for the WT clergy--branch oldsters, COs, DOs.
As many of you know, going on an internation convention tour is very expensive, and they want you to book an entire tour package with their chosen company. They don't necessarily demand that you book their flights, but at least the stay at the convention city has to be booked through the special travel agency. With a tour group like this, for every so many paid travellers, tickets are provided for the tour guides. That's how travel agencies work their tour packages. They round up lots of customers, and for every 16 or so travellers, they can send along a travel agent to take care of the needs of the travellers so things can go very smoothely for the group. Other perks may be thrown in for big groups like free meals or private parties.
However, on the JW convention tours, the free tickets that should go to travel guides that would take care of the details for the travels... those go to branch personel, COs, DOs. Of course, the groups of JWs need bus captains and group leaders to take care of the details that a travel agent would. What is the WT solution? On the application is a checkbox asking brothers if they're willing to be bus captains. So, some shmuck is paying too much for his ticket and has to work during his "vacation."
I've known several that got the free passage tickets, oldsters from Bethel, CO couples, none of them volunteered for anything. This was their vacation, and they had no interest in working for their free passage.
I've also travelled on international conventions where our group endured stupid errors because we had a huge group with zero leadership that knew what was going on. Situation 1) Our entire group was in Moscow when we were supposed to be in St. Petersburg. That wasted 2 days of a very expensive trip. 2) My roommate was a bus captain. He wasted many hours trying to help people find lost luggage.
It's the type of scam that WT would condemn if the Catholic Church did. Frankly, WT has their own greedy clergy that fleece the flock at every turn.