The pistachios cost 10/5=$<<10/5=2>>2 per ounce
He eats 30/5=<<30/5=6>>6 ounces of pistachios a day
So he spends 6*2=$<<6*2=12>>12 per day on pistachios
So he spends 12*7=$<<12*7=84>>84 per week
#### 84