You say Belgium Wilton so I assume you mean woven carpet with a 100% synthetic yarn not just a woven carpet made in Belgium. The term Belgium Wilton is a bit of a trade term for the crap they used to send us. so I would be surprised if carpetright actually call them that. I assume you identified it as a Belgium Wilton.
Synthetic wiltons have their place as contract carpets in hotels, airplanes, trains and other high traffic areas. They can be this expensive and some of the quality contract carpets are even more depending on pattern, quality and were they came from, warranty etc.
You say that the Axministers were cheaper, Axminster is not a sign of quality anymore, Axminster Carpets Ltd make and import and sell under their name tufted and flatbed weave carpets. Punters buy them thinking they will last 30+ years like the one they are replacing. Axminster can nowadays be in the name of the carpet without the carpet even being made in England or even being woven or wool.
Belgium Wiltons properly fitted and properly cleaned are not a problem, problems arise when the cleaner doesn’t know what he is doing and/or the carpet hasn't been properly fitted.
Also Carpetright like all retailers have to advertise something for 28 days before they can discount it. Most of these retailers buy the carpet in knowing what its worth and don’t expect to sell any of it, then overnight the price drops to 50 or even 75% off and they sell it like there’s no tomorrow. We all fall it, that’s why they have so many sales.