If there are 3B bp in the human genome, then the write the whole thing for $1000 it should be $3.3e-7, which is a whole lot less than the quoted $0.02.
The comparison is rather confusing because this article is not about synthesizing genomes, but individual genes. The $0.02 seems to be just a somewhat arbitrary number at which DNA synthesis isn't a large cost factor anymore.
The genes that are typically ordered are a few thousand nucleotides long, synthesizing the whole genome would be an absolutely monumental effort and probably out of reach for now. The largest artificially synthesized genome was done by Craig Venter and that had only about a million base pairs.
If there are 3B bp in the human genome, then the write the whole thing for $1000 it should be $3.3e-7, which is a whole lot less than the quoted $0.02.