Everything that is cheap is relatively cheap. Nothing is cheap in absolute sense. Most of ut is based on my ginancial situation if I have zero € everything is expensive.

Or the other example how low number does bot make someyhing cheap. If 1 byte of mobile internet data costs only 0.01€ is that cheap or expensive? But it is only 1c.

To talk about cheap or expensive you are always talking about either how much similar items usually cost or how easily you specifically can afford it. But it is always relative.

It costs as much as normal house closer to the city. This makes it cheaper than one would expect for a giant historically important castle. If those were built today by modern standards they would cost much more.