22 years of experience in e-business/e-commerce in managing the full spectrum of related technologies and strategies. From store setup, optimization, and overall workflow design. A treasure trove of information on merchant accounts, anti-fraud technology, web hosting, domains, encryption, VoIP, Cyber security, PCI-DSS, HIPPA, startups, and much more. I can provide highly detailed insights that will save you time and headaches.
Magento is on it's way to becoming the number one e-commerce engine. It is a beefy solution, but if you can use e-Bay you can use Magento if you dedicate the time to learn. There is a comprehensive user manual you can download plus 1000s of how to videos on YouTube.
Magento does need a customized hosting environment for proper optimization and load handling, which will cost more than the average mass web hosters out there.
Magento is becoming like the iOS ecosystem with an App Store where you can add a lot of 3rd party features easily. This is a very powerful aspect of Magento.
Main question you need to ask, is: "What is the real potential of my web business?" If you see a lot of sales and large gross numbers being processed, go for Magento. If this is just a hobby of yours, then just stick with the most basic infrastructure possible that does the job.
Also, keep in mind, end of 2015 Magento 2.0 is expected released and will have a lot of changes. Anything you build with it today, expect a large effort in upgrading in the future.
The advice of going with a pre-made system is sound. No one unless they have gazillions of funding builds custom web stores anymore.