For cases where you are involved, the scheduled docket updates are a risk management tool designed to provide you with updates as to changed docket entries. How often you schedule these is a trade-off between the risk side and the cost of pulling the docket sheet.
If you are concerned about the cost, you could schedule the alerts (the docket updates) on a less frequent basis (for example, weekly or monthly). This would minimize your PACER charges.
Bear in mind that the real-time alerts with the filings attached are provided free of charge as part of the professional access.