Starting Monday, the VisorPhone will sell for just $49 with cellular service activation. The add-on unit cost $299 when it was released late last year.
Handspring had been running a promotion that sold the unit for $99, but only when purchased with a new, high-end handheld.
A Handspring representative characterized the price cut as permanent, aimed at spurring sales.
"It's a great product that wasn't selling at the levels we'd hoped," the representative told CNET News.com.
The latest move follows a more modest $50 price drop in May with service activation.
Service plans range from around $30 to $150 per month. Without service activation, the VisorPhone will still cost $299.