With the expansion of Google Glass' Explorer program earlier this month came more digital-eyewear shoppers—and, not long after, more scrutiny. Once Glass' second purchasing wave got its hands on Google's wearable tech, a few cost-curious shoppers didn't wait long to take their new, $1,500 devices apart.

Who can blame them? For more than a year, Google has stuck to Glass' massive price tag, making it tempting to pick Glass apart and figure out how much its tiny, custom parts contribute to the sticker shock. Immaterial costs like research surely factored in to the high price, but by what percent?

The latest estimate making the rounds came from Teardown.com, a subsidiary of IP consultant group TechInsights, who raised eyebrows last week with a guess for Google Glass' BOM: $79.78. That 94.7 percent shrinkage was low enough to elicit a Google spokesperson's response of "absolutely wrong" in a Wall Street Journal report.

Glass received a few teardowns after its commercial launch last year, but they hadn't come hand-in-hand with detailed part-cost estimates, with the exception of a China Post report singling out the eyewear's liquid crystal on silicon display rig as having an estimated $30 cost.

Teardown.com's estimates mostly seemed reasonable, at least on a wholesale basis: $5.66 for a 5MP camera, $13.96 for a processor, $8.18 for 16GB of NAND memory, and so on. But compared to China Post's 2013 guess, Teardown.com's estimate for Glass' high-PPI "display/touchscreen and glass" seemed too cheap to believe: just $3.

"25,000 versus a million"

"Our [estimated price was] for the imager, about the size of a dime, which creates the display itself," Teardown.com costing expert Al Cowsky said from his Chicago office. Adding a simple prism projection rig to that imager bumps the total display estimate to roughly $5, but even with that in mind, "we've heard feedback that that might be a bit low."

Though Cowsky remained largely confident about his overall estimate, he readily fessed up that the report will soon receive a few revisions. For one, he and his team made a mistake by assuming that the Glass employed a TFT type of display as opposed to the LCOS rig. "We were thinking, OK, it’s just a TFT using prisms to project," Cowsky said. "Apparently it’s not."

Since Teardown.com posted its report, Cowsky began immediately double-checking that figure by reaching out to manufacturers and IT experts. "Right now, it'll cost you $30 for 1,000 of those [LCOS] pieces," Cowsky said, and he's confident that price would come down for a direct, larger-scale purchase from a company like Google. "Where [the price] goes down from there, I'm not sure. If Google's buying 25,000 versus a million, it'll be quite different."

The rest of the materials, on the other hand, have been found in wearables and other devices already on the market, particularly Texas Instruments chips like the OMAP4430. Their price can fluctuate based on totals ordered, as well, but Cowsky is far more confident that prices on the processor, RAM, camera, and other parts will remain firm.

Parts versus R&D

"If I had to take a guess, I’d say somewhere between $90-95 is where it’ll end up at," Cowsky concluded, factoring in price bumps to both the display and the mechanical housings. "It could be a little lower, even." He couldn't confirm when Teardown.com will post an updated Google Glass estimate, but it's "definitely on our priority list," he said.

Luckily for the estimators at Teardown.com, they're only interested in the raw wholesale prices of parts: "When it comes to development costs, things like that, we don’t bother trying to estimate," Cowsky said. "It’s too many unknowns in that regard."

(This Google Glass report is one of Teardown.com's only public price estimates, by the way. Visitors are expected to pay big for the company's other teardown details and figures. If you can't wait for iFixit to carve up the Reebok CheckLight wearable band, for example, Teardown.com can sell you those details for $7,000.)

It was fair to assume that the cost bridge between the raw metals and plastics that make up Glass' body and the R&D and customer support cost in making Glass a useful device would be pretty decent. The limited nature of its first few commercial sales opportunities couldn't have hurt, either, as if to say: it's new and rare, so pay up, early adopters.

Still, that's an unsustainable cost divide if Google expects users to wear Glass in droves (and avoid certain restaurants and police officers in the process). By the time Google moves beyond its big-spending "Explorers," a parts cost hovering in the $100 range bodes well for an affordable, wide-release launch, especially as comparable products like Android Wear try to convince smartphone users that they should take the wearable plunge.