Cheap CAT 6 cables- are they any good

Hi all

I am wiring a new house with Ethernet cables( all to be cat6)

- some will be for IR remotes

- some for hdmi extension ( for long distances of 30m back to hub with hdmi pigtail converters)

- some just for data

I have seen 25m pre terminated cables in rapallo for about $50-60 and I've seen them on trade me for $12-20

What are the issues with the cheaper ones- anyone had any bad experiences ?

Cheers