Be interested to know exactly what 'structure' gets added to your hours building for £1500. Do they provide recommended routes and the odd check flight?
I would be tempted to save the money (may put to wards an imc) and have a look at the requirements for the CPL xc time etc and structure your own hour building. Maybe do the odd hour with an instructor to make sure no bad habits are creeping in.
p.s enjoy your hour building, its a great opportunity to go and see places. Your not likely to be in a position to have 100 odd hours to burn again. I wish I had made more of mine.