I know that. I just think that if you compare them to usd you should calculate as if the market cap wasn't changed the last three months.
PIVX had a big jump I think about two months ago from average market cap $100 million to $200 million and now it's $180 million. Zcash had $600 million market cap and know it is $400 million.
If the market cap wasn't changed the difference would be a lot smaller.
In your example without the market cap increase you would still have $10K of pivx but you would have about $6K zcash. I think this is a better way to compare them.
Don't get me wrong, I love pivx and I'm all in it. I just think that your numbers are a bit misleading because of the market cap change.