Yes, those were all my assumptions as well - that is until further clarifications that comes in the fine prints.  This is much like a Alonso Soto report, the basic frame works are correct but somethings are left unsaid. 

Of course setting a sky high base price would alleviate much of the bite, but published reports so far seem to push the fact that mining companies should rush to sign their contracts now.  That means the governemnt is leaning toward using the current price as the base price. 

Frankly trying to establish a $1,000 price for gold for example could be justified through an economic model, but how many companies would want to sign a contract on that basis?  This is at best a "best guess" figure, do I want to commit my company's resource on such a pie in the sky number?  If I were the Ecuadorian government would I commit to such a number that could never be attained?

Too many question still and not enough answers.  One thing I do know.  This tax is a bad idea and may cost Ecuador dearly at the end.