I would strongly recommend that anyone thinking of paying up front runs a credit report on the school in question before doing so, or at least the limited company that operates the school.
They can be obtained from the likes of Experian for what is a very nominal amount in comparison to what you risk to lose, and will show a lot of pertinent information such as whether the company has made a profit or loss in the last few accounting periods, what their net worth is, whether they've incurred any court judgements etc.
This will give you a very good indication of the future prospects of the school. For instance, I ran checks on a number of places I was considering and one in particular showed heavy losses and a net worth of minus £200k. Didn't stop me considering learning at that school, but I certainly wouldn't give them a penny until services or goods had been received.
If anyone wants any assistance interpreting a credit report then I'm more than happy to help!