My first Bernina, a 440QE had a BSR and that is what convinced me to buy her AND to attempt FMQ ing. I now have the 730 which also has the BSR and I use it whenever I FMQ. I also have a Juki on a frame and it has a Cruise control (stitch regulator). Some say it is like training wheels, so perhaps someday I will be good enough to FMQ without a stitch regulator, but for now, without one, I wouldn't do any FMQ ing.
Perhaps you could get a good deal on a gently used model Bernina at a dealers and then use it to trade up in time. They really hold their value. Also, if you are looking to get the machine in 2011, look for a quilt show in your area, you can get some great deals on almost new machines used for demo at the show. Good luck for whatever you decide.