Start with an appropriately-sized Hefty clear tote with the top held on by latches:
https://www.lowes.com/pd/Hefty-15-Qu...Lid/1000505523
Add a small heat pad and thermostat, two cheap hides, melamine or plastic pet bowl from the dollar store, IR/point thermometer, and you're still under $100.
Very little in that starter kit is appropriate for a ball python.