Open source vs proprietary (custom coded) system

Recently, one of my old friends asked me, if he should opt for open source solutions or should go for a custom solution from scratch as he wanted to have an eCommerce website. Open source is in the market for so long and still, there is confusion about this and this prompted me to write this post.

We have two categories

1. Open Source
2. Custom Coded

ADVANTAGES

Open Source

Some of the open-source solutions are WordPress with woo-commerce, OsCommerce, Joomla, and Magento. These systems are easy to install so the speed is there, you just need to give new skin and everything is ready. These platforms have given birth to a new industry where people

- create new plugins/ addons for additional functionality
- create new themes that are available on negligible costs

And then you just need to download/purchase new plugins and themes. You just need to activate or install these plugins, themes and all work is done and finished. Your website is ready and you can easily launch your website very fast.

Custom coded system
The entire system is done by a single source so there will not be any compatibility issue. That way open-source systems help in less costly and high-speed delivery.

DISADVANTAGES

Custom coded system
This is a costly and time-consuming approach. The client may not have that much budget And/Or time.

Open Source
I have seen only WordPress, Magento, OsCommerce and Joomla as open-source. Based on my experience with open source systems above, I would say that

1) These are very general systems and to use these properly... a technical person will have to work on these systems to get the job done so the advantage of low cost evaporates there only.

2) Plugins/ addons are developed by industry people and if you look at the plugins of WordPress then there is no structure fixed that is followed. Means there is always a chance of security loophole

3) If I just want to sell one product then there is no need for any of open source systems as these are made for large systems where an unlimited number of categories, subcategories, and products can be handled so the client will be wasting his/her time is learning the system.

4) None of the systems is complete and you always need some plugins to install that may have a security loophole

5) Magento has a large learning curve and by the time you learn it... they come up with new version and in the new version, your old understanding never works... so you are going to purchase the new ebook of every version and developer will be learning that too... so time and money both get wasted. At least this was my experience 8 years back and I stopped using it.

6) As all plugins are from a different source so its normal to have compatibility issues between plugins as well as plugins may not be compatible with the newer version. Every plugin has a version. So the client will have to deal with the upgraded versions of WordPress as well as versions of the plugins that are installed. Internet is filled with such posts where people are facing problems after upgrade to the newer version and the client pays to get it corrected.  So practically the client ends up paying more.
 

RESULT
So the money client saves by having a pre-built system... same or more gets invested in customizing the plugins and learning the new version
 

SUGGESTION
So I suggested my friend that in place of using an OpenSource ... he can use a closed source custom-coded solution that is already pre-built. As its pre-built so developer already earned from it so can be given at nominal costs by the developer and its readily available so will also save time.