Ballpark on buying freehold on house

[Minimalme]

Very roughly, how much might it cost to buy the freehold on a house with only 6 years left on the lease?

I'm thinking 40k+ but have no idea.

Completely depends on the house. A massive mansion in Belgravia, millions and millions. A two bed terrace a few tens of thousands. it would be very close to whatever the freehold value of the house is there is a calculation that you can do to work it out to do with the marriage value

The house is going to auction but similar properties with the freehold go for £350k.

It might go for 100k at auction.

In which case the extension would likely be something around 250000 ball park. But that is very very rough. It is not a good buy at auction unless you really know what you are doing.

Thanks - it has a really low starting price which I guess is why!