Isn't that the same thing?
At this moment in time, i'm sure if you agree to pay in full for any flying you do at the end of each day and agree to keep, say, £50-100 in credit, then I know for a fact you'll still get a good deal. Schools are suffering at the minute. Any money is better than no money.
NEVER PAY UP FRONT!!!! DO SO AT YOUR OWN RISK!!