So - this is going off topic a little, but still about buying carpets.
Set a budget - a traditionally woven carpet could be £100 a sqM and more. At that price you’d expect it to last many, many years - but do you actually want that? Been there and it’s a now a definite’no’ from me.
Axminster or Wilton? The difference is in the construction. Despite popular opinion, Wilton isn’t better.
Content? Wool, or an 80/20 mix? However, man made fibres are really good these days and it often takes a professional to tell the difference. Cheaper too, so you needn’t feel guilty about changing it to suit a new colour scheme!
Broadloom or body? Do you want a carpet 12 ft wide, or in narrower widths, sewn together in situ - the latter will produce quite a bit of wastage, especially in matching a large pattern.
Pile?? Deep and luxurious or short and velvety? Then be prepared for what will look like early wear - it’s called pile pressure at first. Also look at the gauge - still measured in ounces I think.
Finally fitting and buy the best underlay you can afford, as well as making any carpet more comfortable underfoot - you’ll be able to reuse it a couple of times.