where can i buy halflings for cheap

you could always try a search on the GW online store for "halflings"

Or you could try Ebay or Bartertown. Both of those are excellent sources of halflings.

but toni and i live in USA and i think bartertown is for the uk, but maybe not

Nope. Bartertown is a worldwide thing, really. I'm in Australia, and I've used it.