Websites don't need to be expensive - but it really depends what you want.
You can get a cheap second hand car for under £100. And that's fine if you're just using it for occasional convenience and when it breaks down it's not a big deal. But if it's something you depend upon for your livelihood then you will need something a bit more robust.
A little 2nd hand Peugeot 206 is fine if you just want something cheap to run that gets from A to B (most of the time). Not so great for a family holiday with two young kids, as I know from painful experience.