Five days after confirmation of Pike River's sale, Bernie Monk has spoken of his regret that families of the 29 men who died in the mine didn't submit an offer to rival Solid Energy's cut-price purchase.

Receivers PricewaterhouseCoopers announced on Tuesday that the state-owned enterprise had bought the mine for $7.5 million.

Speaking to the Sunday Star-Times on Thursday, Pike River Families spokesman Monk said he had considered putting together a bid to buy Pike River shortly after it was put up for sale in 2011.

"The biggest mistake the families have ever made . . . was that the families never put a price in for that mine," Monk told the Sunday Star-Times.

"I have kicked myself since.

"[But] I thought it [the price] was out of our league . . . I thought the mine would have sold for a lot more than that."

Monk - whose 23-year-old son Michael died in the 2010 explosion - said if he had known Pike River would sell for $7.5m, he "would have had a punt."

Families of the Pike River 29 have consistently stated their frustrations at being given limited information about planning towards a possible body recovery mission.

Monk said entering a bid would have provided them greater access, as well as putting them in a stronger position to lobby for the return of their loved ones.

"Not only would we have been in the marketplace for buying that mine . . . but obviously we would have bid a lot more [than $7.5 million] . . . we would have been part of the negotiations for what went on, instead of having to guess.

"At the end of the day we realised nothing was going on about recovery, nothing was going to happen for us, and we would have known a lot sooner instead of trying to fight them day by day."

PWC said payment of the balance of the $7.5m Pike River price would allow a "further distribution" to the mine's secured creditor, NZ Oil and Gas.

Monk said his heart went out to the many smaller non-secured creditors - including several West Coast-based companies - that would never receive the money they were owed by Pike River Coal Ltd.

For that reason, he questioned the $7.5m sale price. "We know there is $30 million-plus of security above ground," he said.

"We are looking at a $4 billion to $5b asset [sold] for $7.5m . . . there is $30m of assets above ground, and we know there is a lot of money underground in machinery.

"Yet we can't pay our contractors out in a town that has been absolutely slaughtered economically, and is suffering badly.

"God knows how many companies were involved around here, all little companies . . . not the big multi-million-dollar companies that can take this on the chin and walk away."

Some of the contracting companies were run by families who had lost loved ones in the Pike River tragedy, he said.

"Some of the families have lost not only their loved ones, but they've lost money because they are not being paid out," Monk said. "I just don't think it is fair."

Thursday marked the 20-month anniversary of the explosion, which claimed the lives of 29 miners and contractors.

A Royal Commission of Inquiry is seeking to establish the cause of the tragedy, as well as investigating a raft of concerns about safety and some of the design aspects at the Pike River mine site.

Monk said last weekend that families had renewed their campaign for entry into the mine's drift, after viewing footage taken from inside the mine.

Ten days ago they were shown footage shot from a borehole about 500m before the rockfall, which occurred after the series of explosions that rocked the mine in November 2010.

Solid Energy said on Tuesday it would "commence planning" for an exploration of the entry drift, but added that in meetings with the families of the 29 men, it had explained it could see no way to safely carry out a standalone re-entry of the abandoned workings as part of a body recovery, and believed the only way that could be attempted was as part of a wider commercial mining operation.

It is likely to be several years before the company is in a position to say if it has a feasible and viable mining plan.

- © Fairfax NZ News