You can do all kinds of neat things with a decent 3D printer. But you have to spend a bit of money to get that printer and the materials you need for your prints. There are plenty of awesome 3D printed products you can buy though. Take this 3D Printed Rotary Phone Case. It is an old school phone case with a rotary dial that spins and snaps back into position. It has a built-in coil spring that lets you dial any number (not for real though).
This Rotary Phone Case looks cool and brings back good old memories. You can’t call people this way, but you can play with the case all day long if you like. The case comes fully assembled. Sets you back $20.