[darkvertex]

If you wanna be ultra cheap and your subject is a still scene you can literally just use any camera like your smartphone and take two pics side by side in short succession, distanced apart by your human IPD (Inter-Pupillary Distance.)

Did you know your index finger is roughly 1 IPD from nail to knuckle? This is useful:

Hold your phone sideways, look where your lens is in the horizontal axis and align your left index finger's knuckle such that you're holding the phone edge with it but your knuckle is lined up just above the lens... Snap a pic. (This will be your left eye pic.) — Now keep your left index straight as-is and with your right hand gently grip your phone and slide it horizontally such that the lens previously lined up above your knuckle is now aligned just below the tip of your left index finger nail. Now snap another pic. (This is your right eye pic.)

Now put them in a collage side by side in Photoshop or whatever, and make it small and cross your eyes. If you kept your alignment fairly you should now have a respectable 3D photo.

Voila! 3D photos on the cheap, as long as your subjects stand still between the two pics.