Several years ago my LQS offered a holiday BOM. Each participant had to sign a contract saying that when we signed up, we would purchase all 12 blocks - I assume this is so the shop would not be "stuck" with BOM's that people failed to pick up. I liked the ease of doing only one block each month and I forced myself to stay on top of it. I purchased a finishing kit at the end of the 12 months - last year I assembled the blocks and did the sashing - and it has sat in a box with everything marked and ready to finish -- hopefully this summer - or fall - or....
Oh, each block was $15 and I know the price was raised in subsequent years.