custom data warehouse in python vs. out-of-the-box ETL tool

[Jim]

On this post, you are talking about Talend and Informatica like both
are
comparable... indeed both tools are comparable in power and
functionality.
But keep in mind Informatica is a proprietary solution, with no access
to the code. You have a license fee + other costs associated to the
use
of Infa.
Talend is an open source ETL able to perform data migration and
synchronization. It's code is open source. You can download the free
version of Talend, Talend Open Studio on the website.
Being an open source tool, you can adapt the software to your
organization and therefore spend less time and money on the
development
of your companies' own software.
Download it here: http://www.talend.com/download.php

Just my 2 cents about Talend and Informatica...