If you need something cheap and quick to do I would go to your local craft store like Michaels or Joann fabrics and get a cheap wooden box. Then off Amazon I would get an arcade USB encoder with the wires included and also get the buttons you want for your button box. You can probably end up spending less than $40 doing it this way although it won't look amazing. Links down below for a quick example
https://www.michaels.com/8.5in-wood-flat-box-by-artminds/10357774.html
https://www.amazon.com/dp/B07BQGH8CL/ref=cm_sw_r_apan_i_WM4SFC3AD2KPTZNV9V50
https://www.amazon.com/dp/B08SKJ6V7Z/ref=cm_sw_r_apan_i_JVJPKD2WF3ZGMQ2DJ22R