It's a tough one as they add a lot of charges at auction end BUT their delivery is dirt cheap so it kind of levels out a bit.
A few on here use them but I can't remember his user name now although he couldn't speak highly enough of them.
For cheaper cars think like this.it's going to need an Mot,£40-50,probably a battery,£40,spare wheel/jack,£40,possibly a vic,£41,possibly a v5,£25,usually about £100-150 on top for fees so by my quick calcs that's between £200-300 on top of the car.
It depends on so many factors,like right now I have a complete Corsa c 1.2 sxi I broke for spares after it flipped in the snow last year.the roof was gone but literally all the panels were ok,it looked like it hit both rear 1/4's then kind of flipped on the snow!!I recovered it for the guy who turned out to have no insurance as he was pissed up,ouch!!I gave him £250 for the car and i didn't charge him for the recovery.
I've been looking at Corsa c's in good nick and their anywhere from £1800-2700 for say a 52/53 plater.I could be cheeky and plump for a newer,say 55 plater but the headlights and bumper differ slightly but it might be worth it as they fetch £3500.
Looking on copart they do seem cheap, especially if I want an earlier one on a 52 they're as low as £6-700 but then some 55 platers were £2500?factor the costs in and it could stand me £3000 before I paint it up so no margin there.
As lhd220turbo said,you really want to stick to cat d or unrecorded unless it's one to keep or literally pence,although the cat c's on there seem mega cheap.
Avoid eBay for salvage unless it's private as some of the prices on there are more than you can buy them straight!!!
There's loads of yards out there and sometimes a few even pop up on autotrader now and then.
I've seen a few from the old d hales and they were total shit.a boy who used to work for me bought a load from them and they always had mechanical issues as well as being generally tatty as fuck,no stereos,dead batteries,no spare,mismatched interior trim etc.
Keep an open mind and do your homework and you should be ok.