A reptile rescue in my area often gets donated set ups with the reptiles. Since they already have caging and so many people who adopt want to buy new, they often sell the used setups for money to run the rescue. They get tanks, cages, thermostats, heating--the works. There might be something similar where you live.

I also once belonged to a herp club. People often sold off their no longer needed set ups at reasonable prices. I know that it's not always available, but I've seen really good stuff (and bought really good stuff) from my old herp club newsletter. Since you are trying to get things together on a budget you might want to look into these things. I cleaned the cages out good with bleach water and let them dry in the sun and there were no issues.