Why are some of these Companies so Cheap?

The first questions that needs to be answered are:
Are you looking for backup for personal or business data?
Do you have a server of desktop / laptop?
Do you have more than 10 GB of data?

If you answered Personal, Desktop/Laptop, and Yes Less Than 10 GB you may be a fit for one the "cheap" price solutions available. However, if you are a small business with more than 10 GB of data and especially if you have a server you will require a higher end solution. The issues with the cheaper price solutions lies with time, connection speed to vaults, security, and reliability.

Make sure the company you are considering for data backup fits your specific needs.