That's what Illumina will tell you. But that really depends what you mean by "a genome" and what you intend to use it for. Getting anywhere near the quality of the Human Genome Project is not possible.
That is an unrealistic and inappropriate metric to use.
The HiSeq X isn't mean for making new human reference genomes. It's meant for re-sequencing at scale, and speaking from personal experience, it does an incredible job in quality, speed, and cost.
Even if we could reach reference assembly quality with a hiseq run, we wouldn't want to use it that way. Having reference genomes and annotations (hg19 and hg38) means we can compare and contrast individuals from a common foundation. It would increase the cost and time of genome analysis 100 fold if we had to do denovo assemble for each individual sequenced.
As for pacbio, if I remeber correctly, their cost was low (high equipment cost though) and sequencing was relatively fast, but at a reduction of accuracy. Never dealt with them first hand though.