I found a great guide for investing in bitcoins in UAE that also works for Ethereum with 2/3 of the methods. https://www.smartbitcoininvestments.com/buy-bitcoin-in-dubai/
If you live in Dubai, Saudi Arabia or any of the Middle Eastern countries including North Africa then BitOasis is both a great exchange and app in which you can purchase Ethereum. They also have a dedicated multicurrency wallet which can not only hold your ETH but also your Bitcoin, Litecoin, Bitcoin Cash, Stellar Lumens and the rest.
The other option, for large investors, is to go with Regal Assets. They offer a Regal Cryptos program which allows investors to purchase any cryptocurrency of their choosing and put it inside of a retirement account. Investors can also perform cash deals to store their funds in cold storage inside of an ultra-secure vault located in the DMCC
zone of Dubai, UAE. I would say this makes Regal a pretty good bet for investing in Ethereum in the long term if you are worried about security or lack of knowledge when getting started. They also have a live customer service staff who can answer any of your questions.