The claims surfaced on Weibo alongside images that show Apple's next device in a copper colour.
Luo Zhongsheng, an executive at Taiwanese manufacturing giant Foxconn, published a (now deleted) comment on Weibo claiming that Apple's upcoming "iPhone 8" won't come cheap, 9to5Mac first reported.
The problem lies with the iPhone's organic light-emitting diode (OLED) display, which Apple tweaked specifically to accommodate the phone's new design.
If the rumours — as well as Apple's own leaked images — are correct, it will feature a so-called "notch," which places the front sensors in the top centre of the screen and leaves extra screen real estate at the sides.
Zhongsheng said the extra work required for this form would lower the device's production yield — essentially meaning it'll take longer and be more expensive to produce.
"The OLED's (production) yield is only 60%," Zhongsheng wrote in his post, confirming recent reports that mentioned the same figure. "Cutting the display into this special shape looks really difficult, and the cost won't be cheap. I estimate that the iPhone 8 won't be cheap."
In addition to Zhongsheng's comment, some new pictures of what seems to be a copper gold iPhone 8 appeared on Weibo. There's no way to confirm that these are real, and no iPhone has previously used this colour.
So far, rumours have suggested the iPhone 8 will come in traditional black and white, and possibly a new "mirror-like" finish.