Does anyone know what the odds are of getting a Lv.X card? And does any know where I could get boxes of Unseen Forces, Fire red leaf green, or sandstorm cheaply besides Ebay?
^You rather mean, exactly the same chances (each pack still has about a 36 to 1 chance to have a LVL X) but just a higher chance you'd get packs from different boxes. For the odds this shouldn't chance anything, I think.
It is currently about 1 per box for lvl X. As for those EX set boxes I can only help you with an unseen forces one if you are from England or can afford to ship to your country (which wont work out cheap). Not seen SS or FRLG for a while. If you are english then search unseen forces here- www.cardempire.com but as I have not checked in a while it may be out of stock now. That is about the cheapest I can find I am afraid...