Yep Daryl..agree. Great moulds are all well n good, but if the parts are popped from mould before cured, will be @*!# and twisted, Had it happen twice lately......once was my own fault for buying cheap, but the other was from a rep supplier. By the time I got around to checking supplied part, was too late to moan about it. Managed to fit both parts but a real ball ache.
Further from this, taking care of the mould is also expensive. Getting the part out of the mould can damage the edges of it so you'll need to ensure that the mould is taken care of to ensure that no imperfections transfer into the end product. A lot of cheap parts are ok in the middle and the edges are where the part won't line up or will need a lot of work. Buy a cheap 350 bumper and have a look around the headlights at the lines, I'd put money on nothing lining up.