hello and welcome to the forums.
congrats on your first bike.first of all surely change the oil.you should definitely change the gas too.for prices i can't tell you cause i don't know how are the prices there.how long are the tires on the bike?cause even if they look good if they have been on the bike while it was sitting in a garage they might not be in the best shape.

hey Brian! wellcome to the forums, have a nice stay
first of all, you should take the bike to the shop (on a trailer) and have it fully inspected! the fact that it looks nice for your eyes doesnt say anything about the bike. first of all, this is your first bike so you have no experience, 2ndly you have no idea about mechanics so the bike probably have many aging problems that you cant see. just take it to the shop, they'll tell you all about its problems, they'll clean all the fluids and will make it as good as new for the right money (and offcourse they will probably know how much it will cost you ).

if and when you buy the bike, make sure to start really slow. i've ridden this bike and its a killer in unexperienced hands, the most improtant thing is to not rush to anything, take your time! this time may save you life! try and ask one of your friends to ride with you for the first few times until you have some confidence on it. if you can, go and take an "Advanced Riding" course, it will teach you things that you cant figure out on your own and it will save your life guaranteed!

if you need some help with guidance ill be more than happy to help you.

glad to help