I signed up for my first BOM in, I think, 2004. It is an unusual quilt made of Daiwabo Taupe fabrics. I did 2 blocks. I did not sign up for any others until last year though my LQS. It is a Thangles Buck a Block. I've been somewhat on schedule with it. I purchased the finishing kit. When I went in to pick up my last block they told me that they had run out of one of the fabrics and that since I've been so faithful they would let me pick up the remaning 3 blocks. So I am now working on the blocks and I'm planning on finishing it for my DH's birthday in September.
Despite the fact that I have at least 10 projects going right now I signed up for another BOM in Daiwabo Taupes. I couldn't help myself!
My feeling is this: I have no problem with the BOMs if they are limited run fabrics, i.e., Daiwabo Taupes. For regular fabrics that can be easily found I probably would not be willing to pay the typical BOM prices. I do sometimes change the patterns or techinques a little bit to make them easier to do. I don't think I would participate in a BOM that requires special rulers to be purchased separately. The Daiwabo BOMs that I have include the acrylic templates in the cost and I'm ok with that. I like receiving packages in the mail and it is a fun way to get a quilt done on a schedule.