I’ve never actually had to replace a pump......
Always been shureflo.
First van and system I set up I transferred the pump across to other vans. Lasted 8 years till I sold the van with system included.
Now on my new van and system the pumps are two years old so I suspect I will get many years more.
Aslong as your not having to run it at 100% then I don’t see a problem.
Also a diagphram change may make it back to new.