Well, as an example. I have a Honda 2" - WP20X trash pump, fittings & hoses that I bought new in 1997 for $560. The pump was $415 & the fittings & hoses were around $145. The fittings & hoses are - male & female couplings, rigid intake hose with strainer, 25' flexible discharge hose. I use it for about 25 hours each spring to pump down a pond that forms next to the driveway.
Opened the pump chamber to check the impeller this spring and its still in "as new" condition. In my use, I pump mostly pond water - not much sand, grit, mud etc that would wear on the impeller.
I've never had to do any maintenance on the unit other than - annual oil change & clean & gap the spark plug. I've always used Stabil in its gas so there has never been any difficulties starting it each spring.
I would definitely ask that you be allowed to start the unit and see how it pumps as a condition of purchase, if you will be purchasing used equipment.