✔ 最佳答案
I know your friend can join ur tour. few years before when my mum went to Europe with HK tour, my sister met them in london. When they finish the whole trip my mum stay behind 1-2 day with my sister in england. (my sister didn't follow the tour back to HK) I forgot which travel company allow to do that.. but i remember my mum joined 1 of big travel agent in HK. I think your friend will pay less fee (eg. less HK-> EU returen ticket) , but he still needs to pay the tips etc to the tour guide. Just remember ask the travel agencies before you book.