This is the whole debate really :/
You can get full Japspeed system, Backbox, Mid-Pipe, Y-Pipe & Decats for £400-£500
Yeah although id be a bit dubious about the quality of the parts but, as we said it depends on the owner, their budget and so on. Its nice knowing you have a tried and tested system under there. There are other makes though that are cheaper than the motordyne and pretty much on a par. One thing i did notice about motordyne is their weld quality.