I didn't knew about the trash bins not reseting. I'm assuming it was already fixed with the official patch 1.0.7.4

There are many places to stock for free.
In Tarant, I like to use the P.Schuyler & Sons (1st underground) house. There are 4 chests to stock everything. The Warehouse is a good option too but further from the shops.
In Blackroot, you should be able to have a free room from Hattaway.
In Caladon, I prefer to use The Sobbing Onion basement.