The most recent charges cover more than $4000 of alleged offending.
Calmer was due to apply for bail today but his lawyer did not appear in court and after several adjournments it was postponed until tomorrow.
The court heard how the teen would ask to be bailed to his parents' address in Whakatane.
The Beach Haven resident was alleged to have provided potential buyers with a copy of his hospitality ID card with his name, and also his phone number.
Once the buyer had deposited the money he was then alleged to have couriered them an empty track and trace bag.
North Shore Police said they believed there might be others who had been caught in the alleged scam and would like to hear from them.
"Inquiries so far have established that the alleged offending has taken place over the past 8-12 weeks but we believe there could be others who've dealt with the accused as far back as 12 months ago, and we need to hear from anyone else who has paid money for a computer from Isaac Calmer and never received it," Sergeant Mike Flatt said.
"We're collating [the cases] here on the North Shore but we have victims from across the country including Papamoa, Tokoroa, Katikati, Auckland, Wairoa, Waikanae and Queenstown."
The downside of buying items on Facebook pages was that buyers needed to be extremely careful who they bought from, Mr Flatt said.
"They're heavily reliant on people's honesty and offer little to nothing in the way of screening their vendors.
"There's no such as thing as a 'gentleman's agreement' any more, and it can be very difficult to get your money back if someone doesn't give you what you paid for."
Anyone wanting to contact the inquiry team with information related to Calmer could call 0508 596 739.
