Home businesses can be expensive, but there are businesses that don't cost much to start as well. Here are a few ideas.
One inexpensive way to start a home business is to set up a website. The site can be used to sell a product or to give information. With an information site, you can make money by joining an affiliate program. Setting up a website can cost well under $100, and can even be free, but you will spend a lot of time marketing your site. If you know nothing about internet marketing, there are websites and books that can help.
Another home business idea on a budget is selling at online auctions. If you start small, the cost in both time and dollars is minimal. Begin with items you don't want around your house anymore, or buy a few items at garage sales. Sell a product you make if that appeals to you. Eventually you can connect with a wholesaler, possibly one who will dropship items. This takes away all the work of wrapping and shipping your products.
If you have typing skills, offer them to local businesses. Often there is a need, and businesses can get it cheaper paying you by the job rather than hiring an employee and paying benefits.
Consider tutoring on a subject you know well. This can be an academic subject or a creative subject, such as music. If you do this in your home you will have very little, if any, startup costs.
Think of what you know and like to do best. Then find a way to offer these services or information to the public. Find a home business idea on your budget and start doing what you want to do.