Does anyone have any experience with these? We've just moved into a property in which the previous owners have put a velux window into the loft and replaced the loft hatch with obscured glass, in an attempt to let light into a very dark landing. It doesn't have much effect however, and so I've been doing some research on light tubes/sun pipes to see if it would be worth installing one. Also interested in the rough cost! Thanks in advance for sharing 