SWR meter, do I need one?

what it says, do I need to get a swr meter to go with my CB?
I had a CB setup years ago in my bedroom, antenna propped up against the wall, CB running off a mains PSU, just plugged it in and away I went, got a pretty good signal too. (only sold the sodding thing 2 years ago, wish id kept it now...)

Trying to keep spending down, so do i really need to spend another £10??

no mate if neads swr in ive got one you can use we will check it on next trip mate

sounds good to me, just waiting on the CB and twig to hit the doormat now, then I can get it wired in (when I've fixed me oil leak!!)