Joda - like KPSouthie said, make sure you are converting the prices. I found that the vendors they gave me last year (they may have changed) were a range - from very expensive vendors to very affordable.
My understanding is the list is suggested, but that you can essentially bring in anyone you choose. I would recommend emailing Diana about any vendor you are using who is not on the list just to see if Ceiba is familiar w/the vendor and whether they have positivie or negative things to say about them. We did that with several of our vendors.
My wedding is in exactly one month from today!!!!! So, if you need reviews on vendors, I can tell you then! (All of our vendors so far have been great to work with!)