My machine shopping list included: buttonhole stitch for machine appliqué, needle down for appliqué and FMQ, good throat/harp space, some fancy stitches which can all be found on most good brands of machines. A good dealer/ store is important for free lessons, support and maintenance.
A deal breaker for me was the Bernina Stitch Regulator for FMQ but my 440 cost about $3000 2 years ago? A lot of the 440's are being traded in as people upgrade to newer machines so you might be able to get one a second hand one for about $1500. If you go that route, make sure the shop warranties it.