It's a status symbol, that's all. You buy one, and show it off at parties.
"Yeah, I'm probably going to take my boat out this weekend, sail down to Kunark or something."
"Oh, you have a boat? Do you have a picture?"
"No, but I have the deed right here. See? It was a good deal at 800,000pp."
*hushed whispers* "Wow, he must be the richest guy in Dalaya!"