I am currently taking a course that teaches Sage 50 Premium Accounting software. Following the course I am planning on starting up a bookkeeping service for small businesses. I've been looking at the different Sage products and would appreciate if someone can suggest which product would be best suited to providing bookkeeping services to several companies. My other questions are:

1. Also I am confused about the issue of "number of users" (if a client is currently using a Sage product and I were to do some of there bookkeeping from my office would I require a package for multi-users?)
2. I also read on the Sage site that there is a $750 fee if you want to use the payroll function. Am I correct because it sounds expensive to me? If I did pay for the payroll module would I be able to do payroll for several clients?

Thank you in advance for any suggestions or information you can provide me.