To be fair to ZCash, the high prices at launch were primarily due to very limited supply and market manipulation. The "screaming dive" is really just heading towards a sustainable price.
Somewhere between $2-$10 is a more realistic valuation (based on other coin valuations) -- it will be interesting to see if the price stabilises once within this range.
Mining is generating Zcash way too fast for the market to absorb. The "market cap" has been holding steady as the priced dropped over 99%.