replaced the leach bed at my home in Derry in 1999 at a cost of $10K. The original leach bed had become obsolete and was no longer functioning correctly. Luckily I had room on the property to put a new one in. My next door neighbor was not so fortunate and had a lot of bedrock. In her case, the new leach bed was put on top of the bedrock (above ground) and cost more.
I had a 200 year old farmhouse in Candia that had a dry well used for the washing machine and draining the bath tubs. This helped extend the life of the leach bed.
I don't know of too many places that have a dry well INSTEAD of a leach bed.
here is an older thread that discusses some aspects of dry wells:
Septic System & Wells - Updating Dry Well System?