In 2004 when I first started out on my own, I was looking for a caddy, went all over Yorkshire to see loads. The decent ones were stupidly overpriced and the decent priced ones were complete wrecks. I ended up dropping on a Mazda E2000 twin side door on an X plate (2000) which was more than I wanted to pay but ended up being the best thing I could have done! Since I've had it, Ive spent about £600 on it (Brake discs & pads, Plug leads, Plugs and filters etc). Can get 3m lengths of pipe in it, 8x4 sheets, full bathroom suites and even managed to squeeze a 3 seater settee and recliner chair in (I swore it wouldn't fit!)
They're few and far between but would definitely give one a look if you drop on one