Freestanding house with a pool for 300k? That is incredibly cheap. Perhaps I should move there.

UK money. Still that works out to about $400k in us dollars. You can find better deals in the US, but probably none with tunnels - and unlikely to be places you want to live though not bad places (bad places in the US that would be around $120k)

Auction pricing.

It'll start out at £300k (to market it attractively) and end up selling for £500k+.

Check the pictures, this doesn't look like a house to me. 2 levels of workshop areas and an office area. Also the swimming pool is in the front yard, thats a weird one.

There's a bunch of potentially unpermitted tunnels under the property. Quite the liability.

It does seem cheap for a house in Reading, even factoring in that it is a bungalow. Maybe they factored in increased subsidence risk?

Suspiciously cheap. There are no detached (what we call 'freestanding') properties on Right Move in the area under £400k. The cheapest is £450k

EDIT: oops, forgot to select the 'Bungalow' filter too (ugh). 2 properties: £375k and £350k (very small, 60m2). Still...nothing detached around £300k

EDIT2: ohh auction...230m2...yeh won't go for £300k, way more