The retail on the Onkyo TX-RZ50 is $1400. Other receivers (Yamaha, Marantz, etc.) are also in the same price range. You are better off stretching your budget and going for a used Anthem AVM-60 processor in the $1900-2200 range. Much better power supplies and analog stages, especially if you are going to use an external amplifier such as the Rotel.
Don't bother wasting money on a receiver. The power supplies and audio stages are nearly as good as a dedicated processor.