Stacked on the floor it's about 12" of magazines
I'm not saying it's a no-brainer because some of the articles are better than others, and some of the material has become obsolete over time, but each issue contains tons of material - including photos for inspiration and design ideas.
The biggest question for you - will you actually read them? If you just buy them to put on the shelf and never get around to reading them I would say any price is too high