How much money to start an eCommerce business? 

How much money to start an eCommerce business?
Your main expense is stock. A good estimation is that you'll turnover that dollar amount in stock 4 times in 1 year. That will be your revenue and your profit will be 10% of your revenue.
You must take no salary, at least for the first few years of business. You must focus on your google ad spend as if it were an employee because it will cost more than any employee you have.
Try to build the business from your kitchen table. Rent the cheapest warehouse you can.
Do not spend any money on tables, chairs, computers, use old machines. See Jeff Bezos and the start of Amazon.
You must remain in-stock. It is vital that sales momentum is maintained and if a product is selling too quickly, you must raise the price to remain in-stock.
I estimate that you'll need at least £250,000 in the UK to have a chance of starting a successful eCommerce business and that will mean you working from 0700 to 2100 every weekday.
Do not start an eCommerce business if you are not prepared for this.