Update price calculation to avoid big differences on very low prices.

add 0.5 to the calculated buying price before rounding it to make it more balanced at very low prices.

shop.lua

@@ -203,7 +203,7 @@ function minercantile.shop.get_sell_price(itname, wear)
 	if minercantile.stock.items[itname].price ~= nil then -- if defined price
 		price = math.floor(minercantile.stock.items[itname].price)
 	else
-		price = math.floor((money/10)/(math.log(nb+2000+99)*10)*1000000/(math.pow((nb+2000+99),(2.01))))
+		price = math.floor(((money/10)/(math.log(nb+2000+99)*10)*1000000/(math.pow((nb+2000+99),(2.01))))+0.5)
 	end
 
 	if wear and wear > 0 then --calcul price with % wear, (0-65535)