We recently had to replace our water heater because of lack of hot water, age (12 years to the day almost) and sediment build up (it was higher than the lower element; we purchased the home 7 months ago). While the plumber was here (we had extreme difficulty getting the elements out to initially change that we opted to call in a professional) he told us that our pipes are most likely in need of decalcifying, which is a product they sell for just over $2000. We are not handy people, nor do we know a lot about plumbing which is why I am asking lots of questions to get some answers before going forward with such a large purchase. Can anyone tell me about this process, if it is needed, if it is something we can sit, etc etc.
There is no relationship between tank sediment and pipe calcification. Unless he was able to show you how your pipes are actually constricted, such as where they connect to the water heater, there is no way anyone can know there is such a problem.
Unless you were shown obvious evidence of build up, this sounds like a complete scam to me from what little information you've provided. I would never call these people again.
AFAIK, calcium build up only occurs where very hard water is exposed to air, it does not build up inside of pipes. You may recall seeing elaborate calcium formations near commercial hot springs built up over decades by spraying hard water out of a small pipe. Despite the huge build up outside, the pipe continues to flow without evidence of obstruction after decades of use.