Homozygous doms

[Simplex]

Soo my question for the day..
Lets say spiders:
After reading the last few days my curiosity was suddenly sparked regarding "super" doms.

Due to them being homo they should in theory throw no normals correct?
As both alleles would throw the spider gene regardless.

I rarely see homo animals advertised, is there a reason for this?
Is there a price difference??

Het dom to het dom would throw 25pct homos, thus proving would be needed of course.. For the visuals..

Thoughts?? Or am i asking a totally newbie question

Thanks for the time.