I mean a Halfords Erde one, not a camper-trailer.
Just got the smallest one (the 102) secondhand despite vowing never to get seduced into that roof box'n'trailer thing where you do take the kitchen sink cos you can 
...
We are going to a small site in the middle of nowhere in N Devon next week. I know we should get a wheel clamp but the cheapest I have found is
this
I know you're all going to say 'Do It!'.. but can I do it cheaper? The trailer is a bit battered and cost us £80.
Ideas?