I've been quote £65 per square metre to sand a parquet floor and seal it with 2 coats of oil. I am in SE London. For London prices, does this sound like a lot. I was surprised.
Also, I wanted to lay about 3 square metres of matching parquet in an adjoining hall and the quote for that was £1000. I have a rough idea of how much the materials would cost, so this also seemed excessive.