I'm surprised no-one's really spoken up for Pentax. Their Super Takumar and Limited series lenses are very fine indeed and some of the K, M and A series are not far behind. There are still 50mm f1.2 examples around and the 50mm M f1.4 is abundant and cheap. Any Pentax lens of any era will fit any K mount body, up to and including all digital models (with an adapter for the screw mounts, readily available, and of course you won't get full functionality from a digital era lens on a film body). Pro level bodies such as the MX can be had for under $100. True, there isn't much of a range above 300mm, but if that's not a requirement you might find a decent Pentax kit will leave you some change out of your $400.
Another to consider, if you don't need a squillion lenses, is the Topcon RE2. I had one for 20-odd years and it never skipped a beat. The lenses were peerless, the body indestructible. I wish I hadn't sold it.