Just for reference, for a Protector Type 6, you'd pay anything between £10-60, depending on luck and condition. Usually nearer the top end. Absolute quality bit of kit though.
Worth knowing what to look out for, as it would be very easy to pay good money for something missing a vital bit.
But, they are primarily flame safety lamps used for gas detection, not illumination. When the flame is at the correct height for gas detection it's quite a bit lower than a household candle. In other words, very dim.