Product review (4 stars): Great price and DOES work as replacement for DA29-00003G filters on Samsung refrigerators.
These are the cheapest replacement filters I found on Amazon.  I paid about $35 for 3 filters.

Although they are not exactly the same as the DA29-00003G filter it replaced, it did fit my Samsung RF266AERS refrigerator, but required a little more effort to twist into place than the original.  Once installed it is secure, does not leak and filters water just fine.

I highly recommend these if you're looking to save some $ on replacement filters.