Karen, best advice I can give you is be patient - there are a lot of cast iron pans out there. You bought that #8 pan for a "top dollar" price, but you got a nice piece of history and a great pan to cook with - that's a Slant Logo with heat ring in case you didn't know - made around 1910-1925 or so. With patience and experience you will find the deals that are out there...
The #9 skillet is a Large Block Logo (LBL) smooth bottom - a newer pan compared to your #8. I'm a "set" type of person who likes to have things that match, but if you don't mind mixing the various logo styles then this pan is another nice piece - not rare by any means, though. Getting close to it's top current value IMHO, provided it sits dead flat with no damage.
Welcome to the hobby, but be careful - it's addictive. Be selective and take some time to learn about the different CI pieces out there, although I've been at it a great many years and I am still learning.
My $0.02 worth....