Twice as long, half the price
Brain-Flak, 12 bytes

(()()[][{}])


Outputs 2. Try it online!

The doubled program outputs 1. Try it online!

Explanation

This code pushes 2 + stack height - top of stack.  Initially, this is 2 + 0 - (implicit) 0 = 2.  When this code is run again, it pops the existing 2 and pushes 2 + 1 - 2 = 1.