SEOUL—Samsung Electronics unveiled its latest high-end foldable smartphones on Wednesday with lower prices than last year’s offerings in a push to expand foldable demand beyond niche devices. The tech giant priced its 5G-enabled Galaxy Z Fold3 with 7.6-inch main screen to start at $1,799.99 in the United States, and clamshell Galaxy Z Flip3 at $999.99—down from the launch prices of last year’s models at $1,999 and $1,380, respectively. The Galaxy Z Fold3 and Z Flip3 will launch on Aug. 27 starting in markets such as the United States and Europe. “There’s definitely demand for bigger screens as people consume more media content, and foldables are the only form that makes big screens very portable… the price hurdle is the issue,” said Park Sung-soon, an analyst at Cape Investment & Securities. Foldable phones, with about 8.6 million units expected to be shipped this year, are expected to account for just 0.6 …