can you use paypal on coinbase? do you need a creditcard? How long do the purchases take?
For paypal I do not know because coincidentally I do not use coinbase, but as far as I know paypal prohibits transactions related to cryptocurrency (CMIIW).
But if you have credit card you can try buy it in Cex.io or bitfinex. For details you can read here
http://bitcoindaily.org/how-to-buy-ethereum-online/Good luck!