to clarify what i meant by that statement partyboy
1 point less in cost is 1 less to buy it for, but 1 point higher in sellprice is 4 with 400% farawaybonus.
so if you had a 7 village you would buy 1k tradegoods at 7k.
But when you sell those at 400% at a 23 village you get 23*4 = 92/each (92 000)
so if you go into a village with 24 price you get 24*4 = 96/each (96 000)
but if you bought a tradegoods at 6 you'd only save 1k in total compared to making 4k.
TL;DR sellvillages need to be very high price for good profit, buyvillages doesn't matter as much.
Especially considering how much pp it takes to lower the price after 7, the prosperity is more worth it imo.