Kitties have jumped in value from a few years ago.
According to the online price guide (
http://www.AntiqueSlotMachinePriceGuide.com), the last two have sold for $8,000 + the juice.
Sooo, I would say $9,000 +/- 15% depending on condition / coinage.
Now you just need to find one. If you do, make sure it has all the special kitty parts because they are typically missing.