I posed this question a little bit ago. There were some good comments. My comment was pertaining more to a wool BOM that I was thinking about but the issues are still the same. My thread is here:
http://www.quiltingboard.com/main-f1...s-t145689.html
I have a BOM that is done with Daiwabo taupes that is from probably 2004(not quite sure) that I am STILL working on. It was so well loved and requested that they have brought it back in the current Daiwabo fabrics. It was about $25 plus shipping each month. However, with those fabrics it is worth it because they are hard to get and expensive at about $17-$19 per yard. So that is worth it to me, though I will have to figure out how I'm going to save for the backing. At any rate, I will be finishing that BOM this year.
I like the idea of a BOM because if you work with others it is fun and inspiring. Also, for those that want to just sew and not worry about coordinating fabrics it is nice and easy. That being said, it is a little bit harder, I think, to stay motivated when you're just doing it on your own - especially if you have many other projects going.