Sharon, Peat moss is sold in full and half bales sizes and is cheaper than one with fertilizer added. Depending on what you're making, clumps can be a design element.
Where are you reading that information about adding or not adding fertilizer? I can see no reason to add fertilizer but why not contact the people that wrote those articles. To me it's the same as adding fibers or arcylic fortifier to troughs, planters, lanterns, etc. You're making your project more expensive.

billie ann, Thanks so much for the follow up. I'll stick with the bales, but I am having soooo much fun...even made a Grot toad house today. Sharon

Sharon, It is a lot of fun and you get to make just about anything you can dream up! In this economy it's a cheap hobby/craft. Billie