Why is there such a wide range of prices for whole genome sequencing services? Below is a list of labs around the country that offer genetic sequencing.  What would be the reasons why they each cost a different amount if the end result is that you get a 90GB hard drive with 3+ billion base pairs for your genome?

https://www.scienceexchange.com/services/whole-genome-seq
Quality
Certificates (is "for research use only" ok for you?)
There is no "common" or "average" genome, some of the prices are for bacterial some for human(4,6 x 10 ^6 bp (E.coli) vs. 3.3 x 10^9 bp(human))