Lift station pumps & gas lines questions

Anyone have any experience with lift station pumps? I’m looking at purchasing a park which has two of them installed a few years ago at a cost of $55,000. The two pumps are installed together and operate alternatively to save wear. It will work on one if the other fails. How long do these things last? Should I figure a couple thousand annual reserve for that day when they need to be replaced? Annual maintenance? Anything to be concerned about here?

What do you think about parks serviced with natural gas? Does the gas company ever take responsibility for the lines? I seem to recall a Frank horror story about gas lines in a park.