I think I have posted here before that close to 30 years ago, a person in my office offered me several cameras and a 400mm preset for sale. I knew I didn't have the money and didn't want to have him haggle me, so I told him I didn't really have the money right then, that all I had was $25.00. He agreed to the sale. So, I got:
No name 35mm with fixed lens
Another 35mm compact camera
Pentax SP with 50mm f/whatever, not the f/1.4
400mm preset lens.
Rolleiflex TLR f/3.5 with stiff focus, but after 30 years still working well
About five years later, I picked up two Contax 50mm f/1.4 lenses from the PX for $20.00 each, and about two weeks later, two more for $15.00. Only because nobody knew the Contax name. Nikon, Canon, Pentax, Yashica, all well known and respected names thank you, but Contax ... ?? With the first purchase I got a Contax 139Q on sale, and the next time, a Yashica FX3 on sale as backup. I still have two of the lenses and the FX3. The Contax died so I have replaced it with two FX 103's before they went above $25.00 on the 'bay.