Kitsie, Her templates are an acrylic material and about 1/4 to 3/8 in thickness. They are quite sturdy. I am able to easily use them to cut a width by butting my long ruler up against and then removing the template to cut a long strip. Makes it easier when there are going to be several of a certain template # to cut. The templates have a hole in the center at one end and I just slip them on a binder clip so I don't lose any. I did put little round sandpaper dots at the corners on the back sides to keep them from slipping when I am cutting. Were they pricey? I looked but I don't see the price marked on them...probably about $15, I am just guessing. I think making your own templates would be fine but I know me and I would never get around to doing that. Oh, and I bought a teeny-tiny rotary cutter (I didn't even realize they made them so small) to cut around the edges of the templates. It is wonderful!
I really do like this BOM. Marti Mitchell's directions are very clear and by using these little templates and cutting off the dog-ears, my blocks just seem to go together so well. I hope you enjoy doing your quilt! Have you thought about getting any addtional fabric and making some pillow shams to go with? My LQS has the extra fabric available so I that is one of the summer projects I am planning to do.