Back fall in the sewer line

[Aaron Lancaster]

The tenant at my duplex recently contacted my PM about their toilet being clogged. The plumber found the cause to be a wad of toilet paper in the line which was due to several bellies in the line. He recommended a camera to locate the issue. After sending a camera in, he sent me the following estimate for $24,000 which seems extremely high. This is what he put in the description of the quote

"We found the sewer line in the left apartment has a cross under slab with a clenaout cap under the slab as well. The back fall is from the cross to approximately 3 feet from cleanout. In addition, from the cross into the kitchen and bathroom of that apartment. Furthermore, from the cross into the next apartment near the downstairs toilet. We recommend removing the old lines as the apartments will continue to back up and will need to be addressed. The only permanent solution is to replace the line under slab. We will jack hammer up the floor from the window in the living room to the downstairs toilet and kitchen in the left apartment and branch off into the apartment next door. And jackhammer to the bathroom in that apartment. We will also be jackhammering the floor inside the closet on the right apartment next to the bathroom to reattach the upstairs drain line. will install new schedule 40 pvc and reconnect the upstairs drain lines into the new truck line. We will ensure there is proper fall in the new line. We will not be responsible for replacing any flooring, sheetrock or concrete that needs to be taken up."

I’m new to dealing with this kind of issue and would appreciate guidance from someone more knowledgeable about how pressing this situation is and whether the quoted estimate is reasonable. To me, it feels like I could simply have the lines snaked regularly to avoid clogs. I’ve owned this property for four years, and this is the first complaint of this nature I’ve encountered, so I’m curious if, by leaving it as is, I could go extended periods without facing clog issues.

Any advice is much appreciated!