Interesting use for a trailer. I used to work at a RV dealership. I am guessing it is a 30 to 37 foot trailer, considering the 3 axles. Also a ball hitch tow rather than a 5th wheel. I guess it's basically a gutted toy haler, retrofitted for the hydroponics systems. You could probably get a toy haler that length for 20,000 to 45,000 depending what it comes with. The upper end 5th wheel trailers went for 70,000 to 90,000 (but they were furnished and not gutted). You could also probably find a good deal on a used trailer (toy haler or not) cheep because of a trashed interior. That wouldn't matter if you were just going to gut it anyway, as long as the chassis is in good shape. With all those
lights you would probably need a 50 amp plug for the hook up, and/or a good generator (there not cheep). As well as a large battery bank, and power inverter.