The people control the price of the MHS, but try to reach a low ROI. And this is directly linked to the Rewards. Is the Reward down follows the MHS price. Increases the Reward, the price of the MHS increases. The only constant is the ROI. So you can certainly say that Scrypt.cc / Admin has direct, not to be underestimated influence on the MHS prices.
The "ROI", days to breakeven isn't constant. You can see it varies a lot. www.sccstats.com
It seems there are a lot of people here talking about scrypt.cc without any direct experience. Right now the major issue is withdraws are very slow. There are several other pending issues:
* After the hack, the yield returned to the holders was 20% and it doesn't seem that it ever was returned to the 100% level.
* 37 MHs missing from many accounts, value ~ 0.03 BTC
* Site chat is down and the Admin hasn't been talking much
Scrypt.cc has been around a long time there have been a lot of problems come and go.