I would think the terrible surface is down to the 3D printing.

All the 3D printers that use the extrusion technique (think glue gun) produce a surface that leaves a lot to be desired. I'm guessing that as the part took 22 hours to print the nozzle on that printer is very fine which has resulted in a surface finish that isn't too bad. The little home 3D printers have much larger nozzles and the print quality is awful IMHO. Depending on the material the object is printed with you can sometimes wash it with solvent (acetone) to smooth out the print but then you lose some fidelity. The granular binding technique generally leaves a better surface finish to 3D printed parts and can even be used to make metal parts but if you think that machine is expensive I wouldn't go looking for a price for granular binding.