1. How long is the study? How many lessons does it contain and how many weeks will the study last? Is that too short or too long of a period to study the particular topic? Will you have to break up the study for Christmas vacation or cut it off when summer starts?
2. Is the curriculum doctrinally sound? Different churches have different teachings about a variety of topics. Is this a curriculum that your Senior Pastor or others in your church would want you teaching? Will you have to edit the material to make it line up with your tradition? Some churches will authorize you to teach anything from the denominational publishing house (i.e. Lifeway for Baptists, Cokesbury for Methodists), but will also allow things from interdenominational publishers such as Group or Youth Specialties without having anyone screen your curriculum. Check with your senior pastor or church board to see about accountability standards for curriculum.
3. How long will it take to get through each lesson? This may be difficult to determine until you've actually done the first lesson, but needs to be considered. If the lesson will take over an hour to cover everything, the kids will be restless (especially jr. highers) by the end of the lesson and you won't have much time for announcements, worship, or games, if those are normally part of your program. Also, can you shave off some of the content in the interest of time and still get the message across?
4. Will the material in the curriculum be relevant to your kids? Sometimes Bible studies are developed to address certain issues in the lives of teenagers. Are these issues really relevant to YOUR kids? Once I purchased a curriculum that was great in and of itself, but it dealt with very heavy issues that many of our kids didn't face. Consequently it was really heavy and somewhat depressing in our context, even though it was still a very well-done curriculum with some of the foremost speakers, teachers, and writers in youth ministry today. I didn't finish the study because I felt like 13 more weeks of this would bring down my kids.
5. Does the curriculum fit your format? Do you want it for a small group study or for more of a sermon-style teaching format with more one-way speaking and less discussion? Many small group curricula can be adapted for the latter style of teaching, but there might not be enough usable material to justify buying a whole study.
6. How much does it cost? Depending on the size of your church and your curriculum budget cost may be a large or small factor. Video curriculum can cost more than just printed material, but will make up for cost in terms of holding the students' attention. Another thing technology has made available to us is downloadable Bible studies. By bypassing the cost of publishing the print media and the costs of shipping and making the material available directly to your computer, you can print and copy it yourself for a fraction of the cost of ordering a book. Some of the best (and cheapest) material I have used is available at Sycamore Tree Publishing.
What would you add to this list as important factors in purchasing curriculum? Have you ever neglected an aspect of curriculum and had negative repercussions? Have you ever purchased a curriculum that really was a home run? What factors made that study so successful?