Google is coming out with bigger, more expensive versions of its Nexus phone and tablet to attract more of the affluent consumers who faithfully buy each new generation of Apple’s iPhone and iPad. The latest Nexus 9 tablet, made by HTC, features a nearly 9-inch screen — two inches larger than the previous version. The device also will cost considerably more, with prices for the Nexus 9 starting at $399 — 74 percent more than its predecessor. That’s still $100 less than the starting price for the current iPad Air, which has a nearly 10-inch screen. The new smartphone, called the Nexus 6, boasts a nearly 6-inch screen, eclipsing the 5.5-inch display on the iPhone 6 Plus that Apple began selling last month. Its prices start at $649 for a phone without a wireless contract commitment (or $300 more than the previous generation).