I purchased the canon 20mm 2.8 for $80.. I would've kept it if it was good.. That lens needs an update if canon will renew that focal distance. I couldn't resist the price at the time. :
5D3, SL1, EOS M, 28mm f1.8, 10-22mm f3.5-4.5, 60mm f2.8, 40mm f2.8, 85mm f1.8, 300mm F4 L IS, 70-200mm F4 L IS, 24-105mm F4 L IS USM, 50mm f1.8 STM, 14mm f2.8 Samyang, Sigma 150-600mm C, 430 EX II, eos m lenses, bags and too much lighting equipment.