The serious koi keeper goes for Kohaku, Sanke, Showa and Utsuri, but they make up a small percentage of buyers. I found that the biggest demand amongst the majority of koi keepers including the water feature owners is for bling bling.
I rather import the Kohaku Sanke and Showa and produce the bling bling myself. (Quantities)
With a Kohaku/Platinum spawning, you can expect to get good quality Hariwake, but also a small percentage of metallic Kohaku/Kikusui which is very pretty?
Your can apparently also cull from a fairly early age by keeping the well patterned babies with good luster.
With this spawn, I should also get non metallic Kohaku (and Platinum), as I used a Kohaku male and female and a Platinum male and female.