When replacements concern very expensive parts (like $1k+ pumps) i generally am of the thought that you should let a professional replace it and if at all possible, observe the process. Even if you can't observe, still let them give it a go-over once. The reason is to make sure you have a working best-practice setup as a foundation. Make sure to mention to the guy (or gal) "Hey, if you see anything the previous owners rigged together let me know and we might want to replace that too"
Small dumb things that just take experience to know can affect your millage greatly. On this specific example, my Dad and I, when i was in high school through college had to replace the wastewater lift into the city line 3 times. It is an awful job (use your imagination) and cost us $500 per pump and another $100 for rental equipment, plus whatever the clothes i'd have to burn afterwards cost. I get my dad's "I don't need to pay someone to fix that, i can do it on the cheap!" mentallity for sure, but the first time it broke after he passed, my Mom just hired someone to replace it. The guy said the 1-way valve was missing, so the pump had to repump water that would fall back out of the line and thus work twice as hard. A cheap fix that would have saved us most if not all of those experiences.
