Certainly, the equipment might become unusable, but rather than disposing of it, they are repurposing it elsewhere. Considering the environmental impact, whether the efficiencies and lower global warming potential (GWP) outweigh the benefits of discarding an already manufactured system, which would necessitate manufacturing anew for compliance, is uncertain.
I would estimate payback period to align with a lifespan of around 10 years, matching the expected duration of some of these systems. This estimate entirely anecdotal.
Basically the premise for YNAB. You’re doing good work and have a good habit and mine set. Once you get more cash flow it will be harder to keep track. I use YNAB it may work for you too.