i say get which ever one you think you will like the most that's in your price range. try not to break the bank since acquiring it is only half the battle. once you have it you will need to house it, feed it, and take care of it. you never know what can happen. if it gets hurt you might have to take it to the vet. that can get pricey. maybe you might have to treat it for mights. not so pricey but still an expense.
if its your first ball and you get the hang of taking care of it( which i'm sure you will ) then beware you might get addicted. before you know it you'll be getting another. so if your price range doesn't allow you to get your favorite, go for the next best thing. this way you can see if they fit into your life style.
but that's just my opinion. what ever you get i hope you take proper care of it and enjoy it. a happy ball will keep you happy.