For Vietnamese seeking to embark on the treacherous journey to a new life in Europe, a key question can be: "Grass" or "VIP"?

People-smugglers offer different levels of service at vastly different prices, anti-trafficking experts, migrants and their family members told Reuters.

"If he took the 'VIP' route, there's a 1 percent chance he was captured. It's the safest and most expensive route," said Nguyen Dinh Gia, who fears his son, Nguyen Dinh Luong, was among 39 migrants found dead in a truck container near London last week. Most are believed to have been Vietnamese.