It is never going to work as a soft refurb. For an investor, this has to be priced as land with redevelopment potential for a single dwelling with an annexe. The existing buildings will all go including groundworks. At £3m plus SDLT and rebuild costs of about £2m (why go lower spec for the site), this will sell very well. It is the land size and location that has the value. It is an incredible location.
Above aside, it currently looks like a batchelor pad for a 1970's/1980's band musician, maybe a known band but not a major band. Maybe some spousal money thrown in. Trust fund on the side, perhaps some low royalties circa £30k a year.
Oh, note the photography. The best way to make a two acre field look like an eight acre field is to lie flat in the corner when taking pictures.