Sewing/embroidery combo machines are typically between $500-700. The embroidery areas on these machines won't be very large, usually 4x4 as a maximum size. You'd be better off finding a good sewing machine with the features that you like and then shopping for a stand-alone embroidery machine (Brother PE770 is a good one that does 4x4 and 5x7).

Like someone else said - ask the dealer about their trade in machines. You'll find great deals that way!