Plumbed Quoted $2,500 to Replace 12' of Piping...Reasonable?

[Logan Allec]

One of my rentals is on septic, and I have had problems with roots down there.

I know very little about what piping and installation cost as I have never had to replace pipes in a property before.

I am curious if the BiggerPockets community believes my plumber's quote below is reasonable or what questions you would need answered to understand if this quote is reasonable.  I don't really have time to get multiple quotes since this needs to be fixed ASAP (tenant currently cannot shower as it is backed up).

He claims that putting "copper sulfite at the joints" will "eliminate any risk of roots growing around the new piping." Should I ask him if he will guarantee his work? Do plumbers typically do that? If so, what are typical terms? Any and all comments and thoughts welcome!

Thank you, BP Community!

Email from my plumber:

We dug up the septic tank and ran the machine in the drain clean out that was installed.  There are a lot of roots in the line again since 12/31/16 when you had it dug up and pumped.  I strongly suggest we dig up the 12 feet of pipe and replace it because evidently there are a couple spots big enough to where you will be having this problem every year with tree roots.

Total cost, parts and labor, is $2,500 to:

• Remove and stack the bricks (there are bricks laid over where the piping is) but will not reinstall them
• Dig up and replace 12' of 4" piping [he didn't mention what kind of piping] from clean out to septic
  
• Put copper sulfite at the joints to eliminate any risk of roots growing around new piping