If you're interested in a shared site, for business or just the experience of having a website, there are a number of factors in cost that can define the quality of your host.
With larger hosting companies, you always have some level of guarantee at a low cost. However, these can always have unexpected delays due to a large amount of traffic.
If you want your website to legitimately represent your business or online reputation, I would go for something that doesn't have to be costly, just not so cheap that you can tell their service is spotty. A good web host has a comparable price, EXCELLENT service (which is a must for most web clients) unlimited data transfers, and a 99.9% uptime guarantee. After that, and a little research, you'll find the webhost that's right for you.