The best decision would be to spend the extra money on a computer lab.
Explanation:
This is because the modern economy is largely information based, and therefore, computer based, and computer skills like programming and web developing are well paid and highly demanded in the modern economy.
Students of the school would greatly benefit from the computer lab, and the value that they would obtain from it is likely to be much higher than the cost of the computer lab itself.
Basically twice means 2 in these sentence twice means more than he earn in short words he wants to say that he wants to earn more than he is earning now
for example someone is earning $500 every month so he want to earn $1000 every month
