The 16-acre site of the former Osbaston House in Maesbrook , near Oswestry, will be replaced by a new six-bedroom house.
It marks a new chapter for a site that was the scene of one of the most shocking crimes ever seen in Shropshire.
Christopher Foster shot dead his wife Jill and their teenage daughter Kirstie as well as the family pets before setting the family home on fire. He killed himself and his body was found in the remains of the house.
Renamed as Waterside House, the site was originally on the market with a guide price of £600,000, but after a lack of interest the price was dropped to £450,000 and then to £420,000.
Estate agents Strutt & Parker confirmed today that the sale was going through.
A spokeswoman for the estate agent said: "The property has been under offer for some time but we're now in a position to be able to officially mark it up.
"It has been on the market since 2012 and we have had interest in the property for the past 18 months."
Helena Tibbitts, an associate with joint selling agents Fisher German, said: "We've had an offer on the table for some time and we're now going through the legal process, which can take a while.
"I hope the estate will make a beautiful place to live despite the tragedy."
Since the tragedy six years ago the site has been abandoned, with neighbours complaining trespassers were climbing over the walls to take pictures, out of morbid curiosity. Groups have also entered the site to mark 15-year-old Kirstie's memory on her birthday each year.
Andrew Foster, the brother of Christopher, said he hoped that the new owners would allow him to build a memorial on the site for Kirstie.
He said earlier this year: "It's our Ground Zero. I'm still drawn to it, it's the closest we can get to the family we've lost. I know that there's a percentage of poor Kirstie still there in rubble that I've had buried."
The ruins of Osbaston House were pulled down in 2011 and the grounds were completely cleared in preparation for a new house, in a different location to the original, to be built.
Information on the property prepared by Strutt & Parker says: "The site occupies a delightful rural position on the edge of north Shropshire near the charming village of Maesbrook. The principal house will occupy prominent position set within approximately 16.27 acres of grounds. The formal gardens lead down to a pool set against a woodland backdrop. Beyond the formal grounds are a number of paddocks suitable for grazing. In addition there is an outdoor menage with sand and rubber surface."
People living near Osbaston House have welcomed news that the site is to be sold.
Residents in Maesbrook near where the Foster family lived said they hope the site can provide a happy home to new owners.
And they are hoping the sale of the former site of Osbaston House will allow the local community to move on and put the tragic events of 2008 behind them.
One couple, who did not want to be named but live a few hundred metres from the property, said they wished the new owners well.
They said: "We're just happy if someone will buy it and someone will do something with it. It will stop all the people who just come by to have a look.
"It will be a really lovely home. It's a decent interval of time to move on now.
"It's really nice to know someone's going forward with it. We're very happy that hopefully someone will be moving in. That will be really good."
Next week marks the sixth anniversary of the tragedy.
Osbaston House was destroyed in the early hours of August 26, 2008, by a fire set by Christopher Foster.
It took 12 fire crews to contain the flames.
Foster, 50, who had £4 million debts and faced being declared bankrupt, had shot his wife Jill, 49, and their 15-year-old daughter Kirstie, and also killed four dogs and three horses which were found in the house and outbuildings.
He then set fire to the house before shooting himself.
An inquest held in 2009 heard he had been suffering from depression, and had told his GP he was having suicidal thoughts.
Coroner John Ellery recorded a verdict of unlawful killing and said Mr Foster had "quickly and methodically" killed his family.
"Mrs Jill Foster and her daughter Miss Kirstie Foster were both shot in the head," he said. "They were shot in their respective bedrooms, almost certainly whilst asleep."
People living in the area say they will never forget the events of that day, but feel that it is now time to attempt to move on.
Craig Gittins, 50, a former landlord of the village pub, said: "I feel they want it to come to an end now. They want Maesbrook to be known for the beautiful village it is.
"I don't think any village should have to go through what the people of Maesbrook have been through. They need an end to this now, they need closure so they can all get on with their lives."
In 2009, Shropshire Council granted planning permission for the remains of the £1.2million mansion to be demolished to make way for a luxury home to be built. The 16-acre site was put up for sale in May 2012.
Charles Green, from The Wood, Maesbrook, commented on the plans saying: "I welcome the redevelopment of the site to restore it to accommodation, with the hope that any new occupants can make an active contribution to the life of the local community.
"At present the abandoned and derelict site is still a target for trespassers."
The site is owned by a national bank, but Greg Judd, senior director of commercial property advisors GVA's corporate recovery team in Birmingham, which has been handling the sale, said: "With full planning permission for a replacement dwelling, this estate – despite its tragic recent history – is a rare opportunity to construct a large country house in a secluded location with a spectacular backdrop of the Welsh mountains."