Two weeks ago, Australian e-tailer Kogan made headlines when it announced that it would sell big name cameras and tablets at cheaper prices than stores. Now, it’s doing the same with smartphones.

Kogan’s list of products expanded this week with the addition of the Apple iPhone 4, Motorola Atrix, Samsung Galaxy S2, and four HTC smartphones including the Evo 3D. For each of these products, the outright purchase cost has been reduced significantly, with Kogan selling the $999 32GB iPhone 4 at $749, for example.

While none of these handsets are available on mobile phone contracts – options that often subsidise the overall cost of the device – they’re also not likely coming in from an Australian supplier, and that may mean warranty issues for buyers.

The Evo 3D is one of four HTC phones being sold through Kogan.

Much like what we reported previously, Kogan’s new products are being sourced from international grey market channels, and the local subsidiaries of the phone brands in question often refuse to support warranties on these products.

A Kogan spokesperson said “At minimum, there is a 12 month warranty for all products” and that customers could “contact Kogan if there is a fault and they will replace it with a brand new unit.” The same spokesperson also said that “In the event of a fault, Kogan will never ask a customer to send their product anywhere but our local branch”.

This isn’t the same as having an officially endorsed warranty, however. We’re not sure if the respective brands will support these imported devices, but we’re awaiting on comments from the affected manufacturers for confirmation.

Going beyond the warranty, there’s also a technical problem to consider: mobile technology. Some handsets use different 3G frequency bands, and if you end up with the wrong device for your network, you’ll receive only 2G GSM data speeds, a much slower alternative to the high-speed 3G networks.

Kogan has said that information regarding 3G band will be on the specifications pages of the products shortly, as per our previous story, read the fine print and check the specifications closely before you hand over the plastic.