I like DIY, too; however, I said that a year ago and have done bugger all about it...
(If I could easily source the fabric, well, that would probably add the D to DIY!)
I got a really, really cheap Sinar bellow a few years ago, expecting a semi-worn out product. Turned out to be NIB stock from Sth Africa. I couldn't believe it when I opened the box.
I should do some work on the fabric. After all, I currently need 7x17", will shortly need 11x14" and will some day need 12x20" bellows.