ok, i'll bite!
as an EC student who has done everything but the CPNE (5 weeks to go!), including all pre-reqs, i would recommend you research a bit before signing a contract. to tell you frankly, those thousands of dollars you will spend could be spent in other ways.
are you a good test-taker? everyone learns differently. some need to read alot more than others. if you can follow an outline and have the main book in the recommended reading list from excelsior, you could read the chapters, or skim them if it's stuff you know just for review, and just make notes. that's how i did it. i never used a publishing company. i did every course with the main book and just read what i needed to. excelsior has a course outline with the recommended books, and tells you exactly what you need to know for the exam.
there are lots of threads on this subject. try doing a search if you want more info from other people asking this same question.
just so you know, you DO NOT need any publishing company (rue, college network, chancellors, etc) to take these exams. they are a company wishing to sell study materials, nothing more. as a student of ec, you get that for free anyways. you can buy the required texts on ebay, try to locate older editions of the same text, go to half.com, etc. that's how i got all my books. i also used the saunders nclex-rn review book to go along. that is a great reference for ec's program. i used some of my LPN books as well, and those are 10 years old! the internet and google is a great way to search for subject matter you need additional help with. ebay also sells used college network guides, rue guides, etc from former students.
hope i helped you out a bit. i know it's kind of hard to figure out how to start ec's program. it took me a few exams to get into the groove of it. another wonderful resource for some of the exams is ec's practice exams. they are invaluable in knowing if you are prepared for a specific exam.
good luck! if you need any more help, feel free to PM me! i'll be glad to help you out any way i can!