The scale was $20, an amp was $8, plus a little for a project box. That plus an arduino board is all that I used.
The scale was an Eteckcity (link below). The HX711 amp module came with 4 half bridge strain gauges (second link below). I used the the amp, but stuck with the strain gauges that came with the scale. Basically, I wired the strain gauges that were on the scale to the HX711 and then wired the HX711 to the Arduino.
https://www.amazon.com/gp/product/B078J9MYF7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B086ZHXNJH/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
