Do I need a ETL?
We use Python. Every programming language -- every single one ever invented -- is an alternative to an ETL.
You never need an ETL.
The questions is these:
Which is cheaper to build? Custom software or a configuration of an ETL?
Which is cheaper to maintain an operate?
Which is easier to adapt to changing requirements?
Why not use a free and easy to use ETL tool such as expressor Studio. You can download it at http://www.expressorstudio.com.