Dont limit yourself only to strat currency. Some are willing to sell for loom points, mw items, cRPG gold, or a "favor" in strat. Prices range a lot. You can get a village for free as Butan said, but most likely you would need 250k-1.5m for a village. Castles range from 750k-2.5m and towns more than 4m. But this isnt really accurate - it heavily depends on sides concluding the deal.
