In yet another piece of favorable news surrounding Apple's recent entry into the phablet space, the nation's leading electronics buyback service said Friday that almost half of its early 2014 iPhone trade-in customers who pre-ordered a new iPhone 6 chose to purchase one of the larger, more premium-priced Plus models.

Gazelle in late September surveyed hundreds of customers who locked in cash payouts for their old iPhones before Apple announced the new iPhone 6 and iPhone 6 Plus. Of those customers, 86% told the company they went forward with pre-ordering one of the two iPhone 6 models that Apple unveiled.

"Demand for the larger, and higher cost, 6 plus is substantial," Gazelle said in a report on the survey results. "Many customers are telling us that they're eager to buy the new iPhone, but Apple hasn't yet been able to meet the demand for the device."

The firm found that 46% of customers ordered the 6 Plus with the remaining 54% having ordered the smaller iPhone 6. That's a much more favorable mix shift towards the Plus than most earlier estimates, which put the slice of Pluses sold closer to 25%.

A higher than expected mix shift towards iPhone 6 Plus sales could serve as a boon for Apple's bottom line during the critical holiday quarter, as the handset maker charges higher prices for — and undoubtedly reaps significantly larger profits from — each iPhone 6 Plus than it does from the sale of each regular iPhone 6.

Gazelle also noted that more than a third (35%) of customers who pre-ordered the new iPhone were told by Apple or their carriers that their new iPhone 6 wouldn't ship until at least October 16th with many not expecting to receive their devices until November 2014.

For those customers, the company also launched Friday a limited time promotion that automatically tacks on a $10 bonus to the cash payout it offers on any working iPhone trade-on valued at $100 or more. Customers who lock in a price quote today have up to 30 days to return their iPhone to Gazelle in the pre-paid shipping box the company provides.