My wife is the artist and it makes her happy to build them, which is a large bonus, but cost to build is actually less than $25, which isn't bad considering. It's built from nice plywood and painted, you just need a table saw, the lights are the most expensive part, $17.69 on amazon: https://www.amazon.com/Sun-Like-Spectrum-Selection-Function-Brightness/dp/B08C7F5N7D
https://www.amazon.com/Sun-Like-Spectrum-Selection-Function-Brightness/dp/B08C7F5N7D pretty cheap, we'll see how well it does with cacti in the next few weeks