£450 is about the cheapest I've found for a set of AP coilovers.
What do you want them for, the looks or the handling? You're not going to get a harsh ride with a decent set of lowering springs, but if you want the handling then coilovers are a little better. Coilovers are obviously the better option, but then again for an everyday drive that just looks a bit better sat on the wheels, I'd definitely go for the springs.
It's completely for looks, its already a pretty stiff ride so I'm not bothered about it being bumpy. I think springs are going to be my best option, its really just to get her lower and sitting nicer on the alloys. Would have loved coilovers just to get that wee bit lower but already need to replace the plastic rear window, a door handle, the heater valve and get the bodywork touched up on top of the cost of the alloys so it's just not affordable