If you have IT issues more than a couple of times per year, a managed service will almost always lead to better cost and experience than break / fix. To start, break / fix hourly rates are typically quite high, so a single repair can at times cost more than a few months of a managed service. With break / fix service, incentives are also misaligned, as the service provider is incentivized to move slowly so that the fee is higher.
Break / Fix Service: Call a local IT service provider to send a technician to fix the issue as a one-off solution. They will likely charge an hourly rate or one-time fee.
Managed IT Service: Call your on-contract existing MSP to fix the issue. Since you’re already paying a monthly bill to the MSP, you likely aren’t charged an incremental fee for the repair.
With a managed service, the provider is incentivized to ensure your setup is optimal to minimize repair calls and costs on the MSP side. MSPs will likely help you invest in a long-term, stable, and up to date technology solution that will reduce issues over a long period of time, while a break / fix repair person has no vested interest in you having a stable solution.
More info: Managed it help desk services