The lens usually outlasts the body
A camera body is replaced more often than a good lens. Check the mount, the available lenses and the price of the lens you actually need before comparing two bodies.
A cheap body with an expensive or limited lens system is not a cheap camera.
Sensor size changes the system
Full-frame, APS-C and Micro Four Thirds differ in low-light performance, depth of field and lens size. A larger sensor is not automatically better for every use; it usually means larger, heavier and more expensive lenses.
Autofocus and video are separate decisions
Stills autofocus, eye detection, subject tracking and video autofocus are different capabilities. If you shoot video, check overheating, recording limits, microphone and headphone ports, and whether the crop changes in video mode.
Handling matters more than the spec sheet
Grip size, viewfinder, button layout and menu design decide whether you enjoy using the camera. Try the body with the lens you plan to buy, not with a small kit lens.
Budget for the extras
Memory cards, spare batteries, a charger, a bag, a tripod and editing software are part of the cost. A used body can be good value, but check the shutter count, warranty and return policy.