[stephenou]

Determine how much value does your product delivers to the customers. Let's say if it saves them $500/month, you can easily charge/they will happily pay at least $100/month.

Regarding what type of plan, you should think about what do your customer demographic look like. If they are same type of people with same type of needs, give them one price. I tend to support one-price only, because that reduces troubles like different settings on the backend, have customers to decide, and communicate the differences clearly, etc.