It'll get better.
The newer the server the higher food prices are, but inevitably it shifts to lumber/iron.
Jus' look at the prices on the older servers.
Supply/demand. NPC10s produce 19,5m food per hit...once people start doin' that, they won't have any need for buyin' food anymore...you can make hundreds of mils of food per day.
NPC10s only give like 500k lumber/iron?

The demand for that is higher and the supply is way, way lower. Food is only high at early stages because not everyone can farm NPC10s regularly.
server5:
food: 9
lumber: 19
iron: 23

I think server4 has like 29 gold/lumber right now as an all-time high.

At early stages havin' food cities might be handy, but not worth it in the long run. Buildin' iron/lumber mills can be looked at as an investment if you protect your goods.