Strata have relseased a version of Strata 3D CX called "CXi" through the Apple Mac store for US$499. I've been using Strata 3D for years (although not much of late...) and used to teach 3D design on it in Horsham. The program has evolved significantly in recent years in terms of subdivision modelling capabilities and in my view its an excellent choice that remains cheaper than the high end stuff. The app store version was a few less features, but that's still a great price. The straight version is US$695.