Your parents are being cautious. Stick to your budget and show them that you are very serious about sewing for a career, go to design school and maybe when you graduate they will be able to gift you with a Bernina. Trust me - most of us did not start out with even a used Bernina, we used whatever was handed down or we could afford and upgraded over a course of years to get to the point of being able to afford (without guilt) our dream machines, whether Bernina or another brand. Patience is one of the virtues you learn by sewing.