Little (sometimes almost unnoticeable to the homeowner) repairs around your property can escalate very easily in the mind of the viewer, & let's not forget, potential buyer.
Something as simple as a frayed carpet edge or missing door runner can lead a potential buyer to believe hundreds of pounds needs to be spent, should they buy the property!
So, in the case of tired carpets, always spend a little time having them professionally cleaned - or you can do it yourself if you have the equipment. There are plenty available at reasonable prices. Or consider a refurbished one from eBay!
If the edges do not meet the door runner anymore, as in the picture above, a carpet fitter can attend & at a small charge, trim & stretch the carpet back into position in most cases.
Sadly, ignoring such an example can lead to a lack of further interest.