Depends on what you want to spend. I think for a master bedroom you should get a decent enough quality 80/20 one for half that . Its really hard to compare sometimes as shops appear to have the same carpet ,but you find that although they look superficially the same and may be called the same make and colour, they are different weights/quality. Sale
reductions, are often from artifically raised prices the month before !
Personally I go to Goodens in Neston. Family run, good choice , no pressure, no commissioned salesmen , and if youre not hell bent on a particular colour or type and choose from rolls they stock in their warehouse away from Neston,they are good value and they usually have some small samples at the front of the shop in a plastic tub ,of left over stock rolls of good carpeting, which are often heavily reduced. Even a non stocked carpet which I chose, was cheaper than Bogans.
Theres always online warehouses too which sell off stocked rolls , but you have to factor in the delivery and fitting.
If it was a spare bedroom hardly ever used, Id just put down anything artificial which looked nice, at the cheapest price as youd probably be sick of the colour and want to change it before it ever wore out.