What country are you in?

I wouldn't bother with Cex.io. Coinbase and Localbitcoins are always good but you may have other options depending on where you live.

Don't bother going direct from USD or EUR to XEM. Options are limited and expensive. You'll get a better deal buying Bitcoin first and then going to an alt exchange like Bittrex. It should be on Shapeshift soon as well if it isn't already.