I cant argue on what some one else charges. Uncovering your septic and pumping it, $200 is somewhere in the ball park. I am a licensed septic pumper. I advise my customers constantally that their septic system might be one of their most valuable assets. Unfortunally most people think that out of sight, out of mind. And that is the last thing most people think about. But when the toilet quits flushing their would comes to a end. A broken furnace or AC we sort of can cope with it till we can get if fixed but when the toilet quits flushing, well you dont have any options. I notice that most septic tanks I open now days have no bacteria action. And I feel that putting anything in your tank is a waste of money. Many will agree with me and those selling it disagree. Most of the things we use in our home today kill the bacteria. Mouth wash, counter top cleaners, toilet bowel cleaners, drain cleaners, many medications, bleach, etc. I tell my customers instead of pouring $10 or $15 worth of chemicals every month down the toilet, just put that much in a cookie jar and have it pumped as needed. Which can range from once a year to every three years. Depending on how many people live in your house, water usage, septic size and leach field. Another thing most people dont know that years ago most of our clothing was made out of cotton. When washed these fine threads went into out septic tank and would deteroiate. Now days we have most clothes made out of nylon, rayon and other synthetic fabrics and bactiera can't and wont eat these and alot of them will float to the top and out into the leach field. As far putting something in your leach tile and telling you it will clean it out. Ask them if they will give you your money back if it doesnt work. You will find out real quick how confident they think it will work. I use to do alot of repairs (72 now, so I just pump) and it was not uncommon to have to dig up the first 10' of pipe comming out of the tank due of sloppy installiation, sometimes they dig too deep right where it comes out of the tank and after 5 or 10 years is will bow or break off. I have seen some people have sucess in calling some who does "water jetting", in unplugging deain fields. Usually chemicals is just a waste to time . Since they had your pipe dug up, they should or could have run a camera down the pipe 50' or 100' and inspected it and give you a accurate diagonisos. I am helping a customer right now who has a aeriator and they did not have it serviced properly and is has plugged the line going to the leach field up. Probably if it was simply dug up the first 50 or 100 ft and cleaned out, regraveled it might be ok but the health dept is involved now and they want her to install a $20k system. Right now all she can afford is to let me pump it every two weeks, which the health dept agreed to. Keep us posted to what happens.