Would it be better to buy a double bass or pedal?

A double bass and a pedal are two different musical instruments. A double bass is a large, bowed string instrument, while a pedal is a device used to alter the pitch of a guitar.

So, it is not possible to compare the two instruments and decide which one is "better". It all depends on your individual musical needs and preferences.

If you are interested in learning to play a bowed string instrument, then a double bass would be a good choice. If you are interested in playing guitar and want to add some variety to your sound, then a pedal would be a good choice.