Starting a business means investing. which means spending money. So you'll need money when running new business. Few decades or years before, a business was about manufacturing, retail or selling and everyone needs specific amounts of money.
Now and with all digital, retail and sell can be done online with the least money possible. An eBay store is free to set. A PayPal merchant account is the same. If you're selling goods on the net you'll need to ensure one month of expenses. Why that?
Matter of security, PayPal is pending each payment received for one month until winning customers trust is there is no complain after a certain period. That's a good thing because it's fulfill the security concerns of the customer.
I know that at this point you'll get much more question about How? to run this kind of business unless most people have seen those kinds before on the net. But behind the scene, there is more than an HTML page. And the most important points are:
-how to get orders?
-how you manage your warehouse?
-how to get payments?
-how to deliver?
I'll try to give maximum of possibilities that can help you reply on those questions.
If you are not yet convinced all that can work, check out this great book from Tim Ferris:
