This is a derived version of Gian Pablo Villamil's Rocket Ornament (http://www.thingiverse.com/thing:37750)
This has been hollowed out, with some decoration added to spice it up a bit. Put a CR2032 battery and a red LED inside for a nice glowy ornament!
If you're printing at home:
Print in 2 pieces (top and bottom) and glue together.
If you're sending it off to be printed in plastic:
Use the whole model. If you adjust the scale in the .scad to around 0.9 you can get the cost down to less than $20.
If you're sending it off to be printed in ceramic:
Use the whole model. You will have to modify the .scad a bit. Increase the hull thickness (lower the scale in the inner_hull() function), then re-export. The spiral holes might have to be adjusted too so they don't get clogged when the model is glazed.