Ah, no, not dense at all! The total price is 100g for the character, including what items that character is initially wearing/using. You can keep the DNA as your property in case you want to clone or chimera it with another.
You see, my Genesplicer is a mad scientist, and they don't come cheaply. 50g is the price of reconstructing DNA samples, and he charges per strand. However, since your pet is being kidnapped, not cloned, then that charge doesn't apply.