Huinesoron, in response to your question above "are they worth it?" This depends upon your preference. VT focuses upon Tolkien's languages primarily, and only incidentally includes lore or philosophy, often because the latter include information of interest to the enthusiasts of the linguistics of Middle-Earth. This is discussed, in part, in the introduction to NoME (which does include versions of many of the most interesting "non-linguistic" pieces published in VT). At least a partial index is found at
https://www.elvish.org/VT/shop.html at the bottom of the page.
If your focus is "lore," then the later issues, which include sections written by Tolkien himself, will be the latter issues (again, somewhat repetitive now that NoME has been published). If your interest is JRRT's languages, many of the issues will be rewarding, though Parma Eldalamberon may be a better (difficult to find and more expensive) option. Some of the earliest issues of VT have little substance at all.