From the Excelsior College website regarding using Test Prep companies like The College Network: About Test Preparation Services - excelsior.edu
The list of books is not huge. You can even use some of your nursing books from your PN program. Many books can be found as an eBook or purchased used for a fraction of the course. There are some who have posted that the TCN study guides are not consistent with the material on the EC exams. EC gives you a free study guide with resources and sample questions to help you to be successful with the exam.
Those who are filing complaints against TCN are mostly people who did not realize what they were signing (contract) plus a loan, did not realize the total cost, failed to complete the courses and/or take exams, dropped the program. Some people like the study guides, but either way you need to be a motivated independent learner to be successful in ANY distance or online education program. Only you can decide if it is worthwhile for your learning style.
You only have 3 days to withdraw from the legally binding contract; be certain to follow the exact instructions in the termination clause and create a paper trail (such as send the written notification by certified or registered mail) if that is the decision you make.
Good luck in your educational endeavors.