Before I upgraded to a true long arm, I had a B-line frame. The original one was not a stand alone, so was set up on a table. It would be a bit of work, but not hard to take up and put away. You can see them at www.tobequilting.com The product is very sturdy. Only thing I had to change were the poles. They may have replaced them with something more substantial not tho. I sold it to my friend who loves it. The smaller the throat, the smaller quilt area you will have. So, with a standard Bernina, you will start with only about 3 inches. As you roll up your completed quilt (that part goes thru the arm of the machine, you will lose more area. I started with a Juki and quickly upgraded to an HQ16.
you might think of looking for someplace you can rent long arm time. If you are not done, you can zip off your quilt, roll it up, and bring it back another day. Just a thought.