Once the buyer has deposited the money he is then alleged to have couriered them a track and trace bag which is actually empty.
North Shore Police believe there may be others who have been caught in this scam and would like to hear from them.
A freephone number has been established and anyone with information can call Police on 0508 596 739.
Sergeant Mike Flatt of North Shore Police says enquiries so far have established that the alleged offending has taken place over the past 8-12 weeks.
"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 Culmer and never received it.
Sergeant Flatt says that police have so far established 7 cases.
"We're collating them here on the North Shore but we have victims from across the country including Papamoa, Tokoroa, Katikati, Auckland, Wairoa, Waikanae and Queenstown.
The victims have all been on various local Facebook trade and exchange pages, for example, Buy Sell Trade East Auckland.
"There are dozens and dozens of pages like this on Facebook throughout the country and it's possible the accused has been attempting this on many of them.
"The downside of buying things on pages such as this is that you need to be extremely careful who you buy from, especially if you're using a site such as your local Facebook page.
"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 'genteman's agreement' anymore, 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 enquiry team with information related to Isaac Culmer can call 0508 596 739.
Isaac James Culmer will reappear in the North Shore District Court on Thursday 8 November.