I learned on a 12" Nolting at work, when I retired, I bought a machine on Craiglist for $1,000., It had a harp of 9" worked on it for a couple of years and sold it for $900. I then bought a HandiQuilter 16 on a 10 ft. table, for $4,500. it has a harp or 16" got it also on Craiglist and that is what I have now.
I am happy with "Harriet", and what I am trying to say is there are used machines that might not have all the bells and whistles but will work out well for you.
Happy hunting.