An Asian parts supplier with a track record leaking iPhone parts says that low-cost iPhone is real.
The longer a rumor about a new Apple product makes it rounds the more we just assume the product is indeed real. That is though not necessarily true. The low-cost iPhone is though very likely to be real. First of all, it does make sense for Apple to do it. Just look at this report claiming that Apple does not reach 2.8 billion potential customers.
Etrade Supply published a blog post (via iDownloadblog) today saying that Apple is indeed releasing a low to mid-range iPhone this year. They did not post any evidence, but claim that their sources said that Apple is working on the budget iPhone.