Depending on the size of your rocket, you don't *need* a 'rocketry' beacon... a personal alarm can be rigged to be put in 2.5" or larger airframes.
Alternatively - if you have even the meagerest of soldering skills, one can be built reasonably cheaply. A flashing LED, a piezo buzzer, and a battery are basically all that are required. I built one with a
556 dual-timer IC, because I wanted to send an audio tone to a radio transmitter, but it's not *really* required.