I'm with
@Tod ********
in this. Many people have been denied entry, even with the money. Some are not even asked to produce it. Once they consider you've been here enough time on Tourist visas or exempt entry's, they simply deny you for not having enough funds.
I'm guessing you could complain, appeal, cry a little but i doubt it will change there mind once they have decided your time is up. Watch the TV programme 'Border control' and how the Brits and Yanks go about it. They don't even need a particular reason. A simple suspicion of any of a whole heap of things on there list, and your not coming in.
Immigration anywhere in the world that has a suspicion of your not being a genuine tourist can lead to a denial of entry. I guess Thailand is just starting to operate the same criteria.