SONY televisions boasting Google's web-surfing system go on sale on Saturday, testing how much consumers are willing to pay to combine access to the Internet with their regular TV viewing.

The high-definition sets unveiled in New York on Tuesday will have LCD screens ranging from 24 inches (61 centimeters) to 46 inches, at retail prices from US$600 to US$1,400.

That's US$200 to US$400 higher than comparable TVs without the software, a difference that threatens to dampen sales at a time when more households are looking after their pennies.

Strong sales of Apple Inc's iPhone and iPad have demonstrated that people are still willing to open their wallets to buy breakthrough gadgets, but persuading them usually requires a snazzy marketing campaign to show why the products are worth the extra money.

Forrester Research analyst James McQuivey said he wasn't convinced that Sony and Google will be able to make a compelling case to turn TVs into a must-have item.

"Google TV is a powerful experience," he said, "but most people aren't going to understand it unless they can see it in action."

Sony's new TVs will be built on Google's Android operating system and will navigate websites with Google's Chrome browser. The system can comb through the Internet, television guides and even DVRs from satellite operator Dish Network Corp to find all video connected to a request entered into a search bar at the top of the screen.

"Finally, you can seamlessly search your favorite TV programs and websites on the same screen, at the same time," said Mike Abary, senior vice president of Sony Corp's home division.