<p>Are there any 3D printing services or something similar to 3D print or injection mold light reflectors? </p>

<p>I'm trying to find something that is similar to PCB printing that allows you to upload a 3D design of a reflector and they will produce this reflector and coat it with mirror surface.</p>

I would not recommend extrusion printers for this, because they are unlikely to produce a smooth enough surface.  To get a clean surface, the irregularities have to be a fraction of visible wavelengths, which is to say on the order of 0.01 micron.
Without knowing what sort of reflector you're thinking of (flat? spherical? parabolic?), it's hard to recommend a specific optimal, cheap approach.  All in all, you're probably best off looking in standard catalogs such as Edmund Optics.