The pricing aspect of backup software is too complex to cover in detail here, but suffice it to say that there are a number of factors that may be included in the total price, depending on which vendor you buy from:
The number of clients that you want to back up
The number of backup drives you wish to use
What type of backup drives you want to use (high-speed devices often cost more)
The number of libraries and the number of drives and slots that they have
The size of the systems (in CPU power)
The speed of backup that you need
The number of database servers you have
The number of different types of databases that you have
The number of other special-treatment clients (e.g., MVS, Back Office) that require special interfaces