[vlad]

Knowing that you enjoy using old lenses, you should consider the Pentax K-01. It sells for about 310$, with the 40mm kit lens. It's not really a DSLR, lacking an optical viewfinder, but it's shaped pretty good, and has the great 16mp Sony sensor also found in the Nikon D5100 an D7000. More than that, the sensor is electromagnetically stabilized. That means that any lens you use on it, no matter how old (k mount, m42 screwmount and any other mount via adapter) gets image stabilisation. Regarding low light capabilities, image quality, and price, it's a steal.
And it also has a very useful focus peak function for manual focusing.