E-commerce from scratch or not
I've no experience with Django. I develop websites using Wordpress and a year ago I tested Magento (not tested it since).
I was surprised of how user friendly Magento was. Both front end and backend. It was really easy to set up. You can easily customize the layout as well using Magento template API.
Here are some pros and cons:
Pros 

Don't develop your own e-commerce site. It's a lot of work to re-invent the wheel.
By using a well know e-commerce product, you will also find support.
E-commerce platforms like Magento are easy to set up and offer the option of changing the look and feel to match the rest of the web site.
You can easily combine CMS and e-commerce
E-commerce platforms like Magento offer the option for custom static / dynamic pages (like a mini cms)
You will save money (development time) by using something that is already developed
Most e-commerce sites handle payment towards different banking providers.

Cons 

Magento does not work on all servers (server configuration). This however might have changed in the past year.
If free e-commerce products like Magento do not satisfy your needs, you need to buy licenses. And that costs a lot of money.
It takes a lot of time developing your own e-commerce site if you want quality and usability. There is no way you can develop a good e-commerce site from scratch in just 3 months.
I need to develop a new site with the e-commerce part. I'm here to get some hints from you on which road I should go on.
The site will have a static part which include some static pages and the e-commerce part for sell the products. I'm a Django and PHP developer but this is the first time I need to develop an e-commerce.
I see there's some solutions like Satchmo for Django and Magento for PHP.
There's also some services like Shopify that provide a pre cooked solution.
These are my requirements:

I'll need to give to my site a custom layout/style, all written by me
I'll need a nice admin interface for view the incoming orders, the average orders for day and other nice stuff  (I see Magento have a very nice panel for this)
I'll need a feature that reports me the products that are outgoing out of stock
Maybe I'll need to implement a custom payment method
Maybe I'll need to implement a custom shipping courier

Of course I prefer Django instead PHP. Anyone can give me an hint? I've never used anyone of this framework/products.
Thank you.
-- EDIT
Deadline is 3 months. Budget ~7500 $. I've three months for finish it.