You have to be careful when paying for a work at home opportunity. There are a lot of scams out there. The legitimate ones are typically when you are paying for a service or a product. When paying for a product, it can be great information for you to use to start a business or website. Don't believe the ones that say "get rich quick." Don't get me wrong there are people who became internet millionaires overnight however they are the ones that produced the product. Try to stay away from them unless you know they are legit. I have a couple listed throughout my blog that are not free but are legitimate, tested by me.
One thing I recommend is to work with some of my free opportunities on my blog here. Once you make money from these opportunities you can use some of the money to go ahead and purchase some of the valuable products that are not free if you choose to try it out. That is how I started out. I used money I got from free opportunities to purchase products I have purchased in the past, ok you don't have to do it this way but it helps if you are short on cash. I also have used blog donations to test products that I have listed on my blog for my readers. Blog donations go to product testing, research, charity and of course I get to get a cup of coffee out of it :)
Just be careful jumping into any paid opportunity please.