Dixie McBride hosts a retreat with nationally known teachers in Fortuna. It used to cost about $500 but I see this year it is over $600. Google "Quilter's Escape."
Quilt guilds often host mini retreats that may be open to non guild members. My guild hosts one twice a year on a Fri Sat Sun. There are usually not any teachers, folks just bring their projects and sew! It is held at a camp and offers bunk house lodging and meals for around $300.
Some quilt stores offer retreats as well or allow others to leave flyers for their retreats. You might ask there.