The monthly fee is set by the package, and choosing a package depends above all on how often your site changes and how much your business depends on it being available. A small brochure site that gets new content once or twice a month is covered by the monthly updates and weekly backups of the Basic package ($149/month). But when new orders, sign-ups or forms come in every day, a weekly backup means risking several days of data; here the daily backups and 4-hour response of the Pro package ($349/month) make more sense. The Complete package ($690/month), with real-time backups, WAF, CDN and a 2-hour response, is built for a high-traffic site whose downtime directly hurts sales and reputation. So the right question is not “which package is cheapest”, but what you would lose if your site went down or lost its data tomorrow, and how quickly it needs to be back.
The second factor is the current state of the site. The initial audit shows what has fallen behind: an old core, abandoned plugins, malware, insecure settings or no backups. These are fixed before maintenance starts; and if the site was built by another team, the cost of fixing them is calculated separately from the monthly contract, because it is one-off work, not ongoing. The audit output is a list of issues showing which are urgent and which can be handled in the normal maintenance routine. That is why a site that has been updated regularly enters maintenance cheaper and faster than one that has been left unattended for years.
Setup time also depends on this audit. For a healthy site, the work moves almost directly to setting up monitoring, automatic backups and alerts; for a site with accumulated issues, the fixing stage takes longer. Keep one point in mind before choosing: maintenance is for keeping your current site healthy. If you want new features, a redesign or a new section, that is a development project and is estimated separately. Keeping the two apart keeps the monthly fee predictable and stops maintenance work being sacrificed to development work.