After months of rumor and speculation surrounding the new Galaxy S4, Samsung finally unveiled its new “life companion” at a very peculiar event in New York City’s Radio City Music Hall last night. The device has already received some criticism for looking a lot like its predecessor, the Galaxy S III, and indeed a number of Samsung’s other smartphones.

Fans are disappointed that the Korean company has continued to use plastic for its new flagship — despite a company executive explaining the decision behind this earlier this month — and that it hasn’t switched to more premium materials like aluminum and glass, following companies like Apple, HTC, and LG.

If you’re one of those fans, then you’re going to be even more disappointed when you hear the latest Galaxy S4 rumor, which claims Samsung developed a number of prototypes for the device, then brought the cheapest one to market.

Sources for SamMobile say that Samsung tested many Galaxy S4 prototypes — all with different designs built from different materials. In fact, there were so many prototypes that the “insider” wasn’t completely sure which one Samsung would actually unveil at its event.

There was an all plastic one with a Super AMOLED display, one with an aluminum frame that had a new “PHOLED” display, and one built entirely from metal.

Samsung chose to stick with the first one — the all plastic one — which, incidentally, was the cheapest to build.

It wasn’t all about cost and maximizing profits, however. The sources claim that the all-metal prototype had issues and didn’t make it through the first round of testing, so that particular handset was no good anyway. SamMobile concludes that Samsung just isn’t ready to build a metal smartphone.

But it could have given us one with a metal frame, which would have felt at least a little more premium than the all-plastic model the company announced last night. So why didn’t it? Well, that’s not completely clear at this point, but Samsung’s YH Lee, executive vice president of the mobile business, did explain to CNET earlier this month why Samsung loves plastic.

One of the reasons was that it’s easy to manufacturer. Samsung knows its flagship smartphone is going to be a big seller, and it doesn’t want any delays that will leave customers waiting weeks for their new device. So using plastic allows the company to build them as quickly as possible.

What’s more, plastic also allows for that removable back cover — and therefore the removable battery — which is more difficult to provide with smartphones made of metal. Look at the iPhone 5 and the HTC One, for instance; both have unibody designs that are completely sealed all over.

• SourceSamMobile