Pricing Monthly Maintenance for Custom Software

I’m looking for feedback or some kind of technical and commercial opinion from consultants, freelancers (anyone with experience in this).

I’m structuring pricing for my development business. The model is custom development, focused on mid-sized companies (logistics, distributors, etc., around 50–100 employees).

My specific question is about the monthly fee charged to keep the system running: I’m considering charging between $12,000 and $15,000 MXN per month.

This payment includes:

• Infrastructure: Hosting on dedicated servers / cloud
• Operational continuity: Monitoring, transactional backups, and database optimization
• Technical support for employees
• Security: Library updates and server patching

Note: Any development of new features or modules is quoted as a separate project.

Do you consider this $12,000–$15,000 MXN monthly range appropriate for the current market, or am I leaving money on the table given the responsibility of managing the infrastructure?