Apartments, like best friends and all-inclusive resorts, sometimes come as a package deal. Four units on the 17th floor of the Sherry-Netherland just hit the market for $30 million under a single listing. The apartments — one of which formerly belonged to Douglas Elliman chief Howard Lorber — include a total of six bedrooms and 10 bathrooms. Lorber bought Unit 1701 for $5.1 million in 2011 and lived there for several years before he sold