Hi there Sprint/Dart 15 parts are becoming more and more expensive.
Check these sites for the prices. https://www.windsport.co.uk/product-category/catamaran-parts/sprint-15/ and this place for Second Hand bits. https://bnrwatersport.com/catamaran-dart-parts/catamaran-parts-dart-15.html
With this in mind regular checking and servicing of boats is imperative.
I know I can't afford to pay these prices for parts.