My cheapest set up for a corn snake was $150 for everything. Rainbow's cage though..... I think I am in the 5 to 600 range.

Cage was purchased for $100 off craigslist 8ft x 4ft X 4ft. Was bear bone cage. around 300 in paint and foam. $30 to 35 for 2 concrete mixing tubs for water on each level. 3 heat panels $40 each and thermostats $25 each to go with them. Random décor around $100... Just did the math. Around $750. Takes 3 bags of substrate at $15 per bag from chewey.com. If I had to build the cage from scratch would have been much more. I think this cage should do her for 2 to 3 more years before needing an upgrade. Then Aurora will be in there and her larger room size enclosure will be built.

I know I am going big here but they need quality of life IMO.