I participated in one (they called it "Blockbusters") a couple of years ago. It went for a full year and at the last session they gave ideas for finishing the quilt. I think it cost $5 for the first block and if you brought the completed block from the previous month for the next installment, you got the fabrics for the current block free. It was a lot of fun and I managed to make every session so my 12 blocks cost me $5. It did get a bit taxing after a while tho - making sure that the I was free to go to the meeting on the first Saturday of every month for an entire year.