I'll comment on the ten ISBN numbers. Long ago,...maybe 15 years ago,... I wanted to write a children's book on the learning disability "dyscalculia". It wasn't going to be a thick book, but I planned to draw the illustrations myself, and also to get it translated into as many languages as possible. Forgive me that I don't remember now the price for buying just "one" ISBN number. (Ah, the dyscalculia, you see?) But, I think that just "one" cost about $100. However, TEN of them cost $200. So, I bought ten. Later, I saw that my ten ISBN numbers had gone up in price and were then valued at $250.
P.S. Okay, so now I found this:
"ISBN Numbers for Books
You also can purchase an ISBN directly from Bowker at myidentifiers.com. Keep in mind that a single ISBN from Bowker costs $125, and 10 ISBNs cost $250."