All camera bodies and lenses (primary and backup) are sent in to either my local camera shop or the original manufacturer for a cleaning. Working with horses, a lot of dust and dirt can get caked up, so I like to make sure my equipment is cleaned and checked.
DSLR body and lenses are calibrated at my local camera shop. While mirrorless equipment doesn’t need this, it’s important for DSLRs to be calibrated with your lenses so that the focus point you select when shooting is accurate and your images are sharp.
I order new SD cards once a year to minimize the chance of any issues I may have. This isn’t really necessary this often, but I find older SD cards (3+ years old with regular use) are the ones that throw me issues.
Every 3-4 years:
I upgrade/replace my primary laptop to a new one every 3-4 years as I find that’s about when it starts to show its age in performance and I want to take advantage of the newer, better features that are available. The one I replaced becomes my backup. By then, my backup is about ready to retire for good because it’s 8 years old.
I try to plan to be able to do the same with my primary body & lense(s) as well and move the ones I replaced to my backup slot and fully retire the ones that have been my backup as by then they are quite heavily used and not quite as reliable.
Total monthly savings I account for to maintain and replace my equipment: roughly $500 per month