I am very happy with my Pfaff Ambition. It sews a straight line without me doing much of anything to guide it! It does not have a scissors function so I guess I don't miss it. It has a bigger harp space than most but there certainly are bigger ones out there. It will be under your budget.
I agree that there is no such thing as a perfect machine, but this Pfaff is perfect for me! The only thing I dislike is that it has a screw-on needle plate. Pain in the butt to have to unscrew it to get in and clean the bobbin area.