So, now I got the same problem. Im at Senuzgda Castle with the following stats:
Senuzgda Castle
Population: 1143
Troops: 54
Gold: 1543
Tax: -10%
Goods price: 14/8
Supply&Demand: +70
Prosperity: +331
When I try to sell something, the base price is 14. I sold it without changing the price, but everything I tried to sell is put in the town center instead. I bought the wares back, losing a lot of money on the tax. Please fix this!
Even if I try to sell 3 goods only, they are put on the town center.