OK I thought he was looking at a visa in country to solve his issue. Good that there is an option that does not require 400k in the bank :). Vientiane is usually the easiest for most types of visas with minimal paperwork. If he was worried he could go to a visa agent and get them to sort out the easiest option for him perhaps.
From Australia, Yep. Be a crappy way to start your holiday if they made an issue of it. But then I have flown from many other places into Thailand and never been asked. Just book a cheap onward or 'rent' as someone suggested in the comments.