Bernettes are, I believe, badged machines, made for Bernina, but not by Bernina. Just like Husky is Viking's badged machines, and I think Hobby is Pfaff's badged line.

Of the two-- Pfaff and Bernina -- I'd take Pfaff most likely, because the presser feet are not as outrageously expensive as Bernina. And then again, I've never met a Bernina I bonded with -- but I can happily sew at any Pfaff or Viking I've ever tried. Bernina partisans will disagree with me. Either way, you'll have good machine, particularly if you do a little extra research at places like the machine reviews at http://www.patternreview.com

Here's a "faq" on buying a sewing machine -- good advice, imho:
http://www.cet.com/~pennys/faq/smfaq.htm

FWIW, I've heard some good things about the Bernina 1008 mechanical from people I trust. Myself, I prefer electronic machines because of the stepper motors, but a good mechanical will outlast an electronic.

Dual feed, btw, is now also available on at least one other make of machine, Janome, as Accufeed. I don't find it particularly useful compared to learning good fabric handling techniques (try Margaret Islander's videos, particularly Industrial Shortcuts).

$1500 was last year's ballpark price.

You will have to visit the dealers and see what you can do - they will not quote over the phone.