Yeah a lot of models among various price ranges have the same sensor and thus same image quality, the extra price just gets you stuff like larger buffer, higher continuous shot rate, more auto focus points, etc, and gadgety stuff like WiFi or rotatable screens.
Find out exactly what your needs are in a body, then buy the lowest price body that fits those needs. Then spend the money you saved on good lenses.
I bought a sigma 17-50 f2.8 right before a convention. It was all the perfect focal range I needed, and the f2.8 really helped in the low light of the con space. I wish I had a different lens when I was doing the studio work, though, a little bit more reach would have been nice, and I didn't need the speed
