Oh dear, not good John, unfortunately, the splitter is not made using a structurally strong method of manufacture as it uses wet lay carbon backed with fibreglass, a pre preg splitter may well have come off better I would hoped. This can be repaired from behind by laminating some fibreglass/carbon fibre and gel coat resin, time would then need to be spent on the front facing area with more clear coat gel coat, then plenty of flatting. There may well be damage to the weave of the carbon due to the break which without spend enormous amounts of itme is not going to be hidden. It can be rejoined though john, it depends on the finish on the front as to if it will be satisfactory.
Price - Hard to say until we have it, but could be joined back together and neatened up for around £40-50 i should think, depends how m uch time you wish us to spend and how much money baring in mind retail price of new part.
thanks
Bic