You need to let your local store/dealer know what you are looking for...and not commit to buying anything as of yet...they get trade ins all the time where people are trading up.
I got a very, very gently used Pfaff CV for a steal from my dealer (they called me to tell me about it). It was cheaper than my class room used Duetta...and I love both machines...
But get the largest hoop size you can afford and the most machine that you will grow into...
It has certainly helped me quite a bit!
Kirsten