This is a bit of a passion project for me, I make custom 3D printed tap handles for the local brewing community. I keep pricing pretty low, just enough to cover materials (filament), a bit of time, and other consumables.
There are lots of material options available, and the ones included in my standard pricing are:
Plastic (PETG or PLA), your pick of colours, White, Black, Grey, Red, Green, Yellow, Blue.
Wood, a bamboo infused plastic, that you can sand and stain.
Exotic finishes (PLA) that may attract a minor additional cost depending on quatity:
Marble
Carbon Fibre
Glow in the Dark
Transparent. (Well, milky transparent)