Sounds a bit expensive tbh. The horizon would have been under 200 in 2008, the carpet about 40 and the canopy also about 40.
The same tent and carpet now would cost a bit more , granted , but I suppose it all depends how much use the tent has had. It could have had a lot of use in 2 seasons .
if its "a used once only and didnt like camping" ,and from someone you know that it is true . fair enough.
But you can buy the horizon 8 new for £250 here the carpet is £42
and the canopies on ebay for about £40 new .
a similar tent to the horizon is the khyam ontario and you can get this for £225 new here
Just looked at the olympus on halfords website and my first impression is that it looks like theres a very small frosted window on the side , and it would be very dark inside, it doesnt look as though theres a big window in the door ? I wouldn't fancy being inside on a wet day with the door shut, would be claustrophobic .