This idea came up to my mind while I was doing business on my village.
So, What if fief owner could upgrade his Fief to get more production points? 5k = 1 Upgrade = 25%(could be less) more production points, next upgrade would be 10k.....20k...
Just like in SP you can build school and other buildings to get more Goods/Recruits/better gear, my idea is similar to this.
Also not forgetting possible exploits, like making goods price 0 or -100% price on some items, it could be limited to smallest goods price 1 and -75% price on items.
What do you think about this?