Hey Carol,
First the disclaimer....if I start to sound snarky, don't take it personally. =o)
I've been having some back issues for over 2 months now and I'm a bit grumpy.
I guess I am of two schools of thought on this issue. For myself, if I am writing an article for publication, I take in to consideration the ease of finding the items required. However, because I am a bead vendor, 99% of the time, those would be supplies I sell. And I think, when looking through many articles, 99% of the time the author has used product that they can either easily kit, sell themselves, or are commonly offered from their suppliers.
Only once in awhile do I see an article written where the item is obscure or one-of-a-kind. For those that are like this, I think the author is assuming you will use their project as a springboard. Replace this one-of-a-kind centerpiece with one that you love from your own stash or shopping trip. Replace this ornate $100 clasp with one of your choosing. More of an inspiration article rather than a repeat exactly type of project.
And most times when someone has written in to a magazine saying they are having trouble finding XYZ item, the reply is usually...."Please consider the components used as an example. Use items from your own bead stash to replicate and make this project uniquely yours."
Lisa Kan wrote her Bead Romantique book by giving her own color names to the seed beads used. Within weeks she ended up having to publish a blog post with the suppliers actual stock numbers as the flood of requests for the exact items used was more than could be handled one on one. Lisa had assumed that the reader would want to explore their own colorways, maybe use her colors as a guideline, but pick out colors that would be similar. Amethyst AB for instance....how far off can you get from that? Well, apparently far enough off that her readers would panic without the actual information.
While I have done some great business due to Lisa publishing that blog, and it certainly made my life easier in being able to help my customers locate the actual beads Lisa used, I still question why someone wouldn't want to experiment a little? Do you really truly want a piece of jewelry that looks EXACTLY like the other peeps who bought the book? Wouldn't you like yours to be unique? The answer is always...."No, I don't want to take the time to figure out colors for myself. I just want to bead the project!"
From this, it is obvious to me that there are those who only like to create an exact replica of what has been published. However, if an item is discontinued, or out of stock for an extended period of time, would you be willing to take a close substitute? If yes, then you may also be the type of beader who could adapt a project using a one-of-a-kind component. If you're not willing to alter, than maybe that particular project isn't for you? ;o)
As for the lampwork artisan, I know many of them that do not make duplicates of their beads, or maybe only make a few. Just like a beader may not want to make 20 pairs of the same earring. They get bored just the same as we would beading the same thing over and over again. However, just because they only offer one-of-a-kinds shouldn't limit them from being promoted in a book. It is the studio artisans that need the most support, rather than the mass producers who knock them off. Just as it is the smaller family operated businesses that need the most word of mouth referrals, rather than the big guns who have the cash flow to pay for their own advertising.
All that said, I do understand your frustration. Sometimes I see a bead that I just WANT to own really badly! Sometimes it just ain't gonna happen! LOL
I hope whatever the project was that you'll consider adapting it to suit your needs. What is most important in beading is that you love what you do. Enjoy the creative process and then feel amazingly good about yourself for what you've been able to create.