I believe in investing as little as possible to get started on the internet. Once some income comes in, that can be reinvested into projects. Even when the money rolls in, a percentage should be used as income, a percentage for maintaining and expanding current projects, and a percentage for new projects.
Getting started can be as inexpensive as one domain and one hosting account. Have several ideas you want to test out? Choose a domain name that is somewhat generic. If you are really strapped for cash, choose a .info, but a .com would be best. I have had 2 sub-domains be on the first page of Google for my keyword (keyword.generic name.com). I tested it with a blog.
I don’t have time or money to redirect the blog at this time. I did invest in a domain name for the blog. Since it was so easy to get to the first page, I decided on .info for the keyword. When I am ready I will redirect it and develop the site to include a web page and a blog. I will use a directory (domain name/blog.info).