I apologize for the long post...

Our house is 15 years old, we bought it and moved in 1.5 months ago. Yesterday afternoon, the master bathroom toilet overflowed, and there was a good inch of water in the shower stall (the lowest point in the house). Also in the shower stall was what looked like grains of dirt/sand, nastiness out of the toilet, and a little piece of carrot that I know was a part of dinner the night before--so all of this water is originating from various points in our house.

I called a national chain emergency plumbing company, and while I was waiting the two hours or so, the water did drain on it's own, albeit slowly. The technician opened the clean out pipe right outside the house, which was full of water. He ran the snake through to the city clean out, and it did look like it got hung up a couple times, but it came out clean and the water drained. He then did run the camera through, and noticed a section about 15' long that was full of water, but no blockage, so he said it was a belly in the line. We watched as he did this, and he said he was making a DVD, but we didn't notice until after he left that we didn't get a copy.

He quoted us a price of $2100 to replace the 15', having to call his manager to make sure he was giving us the correct price. Since we live in West Broward County, we're built on sand and it's a lot of work to dig down 2.5 - 3 feet to get to the pipe (his words), and that's the justification for the price.

My question is two fold--is this a fair price for our area, and is this something we really need to have replaced? We don't flush anything besides toilet paper. I'd like to think that we're not getting taken for a ride, but really, who can you trust anymore?

Various ways to approach this:
Wait for the next time. If it's been raining a lot, especially.
Get 2 other quotes, after you get that DVD. (They want you to hire them.)
Excavation means getting the backhoe to you and back on a trailer, so the price has a high start, whether it's 15' or 155'. The backhoe might be 100/hr, and figure 2 hours travel time, plus 2 men, all day. 2100 might be around what they all will charge. But someone closer to you might be a bit cheaper.

Another tactic: Sometimes you can hold the previous owner accountable, if you can prove that they knew about this and didn't disclose. Difficult, but it's been done.

Thank you for your answer!

The technican who was here said that they would hand-dig to get to the pipe, so no back hoe rental is needed (which makes me have an even harder time justifying this estimate).

We considered the previous owner, but the house was a foreclosure, which was then bought by a company who fixed it up a bit, and then sold it to us. I don't think we'll have a lot of luck there.

Is having standing water that bad? If we don't flush anything besides toilet paper, would it clog back up again? The more I think about it, I wonder if one of the contractors who were in the house before we bought it didn't flush a rag or something similar, which caused the clog.

So hire two teenagers with shovels, then get 2 plumbers out to quote. (The clay soil where I live is like cement so it is cheaper to pay for a backhoe.)
You still need that DVD though, to locate the spot and to show the other plumbers.
It's not easy to give advice about whether to proceed or not without knowing how often it's going to back up. Feel free to wait.

You mean you can't diagnose and solve the problem for free and from states away? LOL :-) Thank you for the suggestions. We're going to get a second opinion, and probably end up just replacing it to be safe.

The price seem in the ballpark, you have to figure if they hand dig it will be a 2 day job you ave a certified drain layer who draws about $30 hr, at least two laborers that are gonn get $15 hr plus materials and premits and have to leave room for profit. So the quote you got isn't that bad, I would get another quote find a family owned plumbing company that owns their own backhoe they probably will beat the bid you got from the national franchise.