Back Again Hunting Some Cheap Shelving for My Greenhouse

Hey ozbargainers,

I'm trying to find some cheap shelving for my greenhouse. Max width of 100cm with a height of up to 1.4 metres. I imagine 4 levels is probably enough as id like some space for plant height. I'm hoping for a solution under $50 but will pay as much as $100. I'd even make my own if anyone knows an easy, minimal tool design. Any help would be appreciated.