Are the textures contained in each material ones you created yourself from your photographs and/or created by hand? or are they from an images you downloaded off of the internet? Do you have written authorization to sell those textures from the owner who created them if you have downloaded them?
Also what resolution are the textures? Are they all 2048x2048? Do you have any other sample images of the materials applied to objects? What are the other 24 kinds of materials we aren’t able to preview?
All of the things I mentioned are what I would want to ask before I can say if it is a good deal or not. 