There are still tanks/silos that are (in my opinion) way to cheap for what they provide. Current prices, with expensive recipes:
Angel's Addons - Ore Silos:
80 Steel
240 Stone-Bricks
Angel's Addons - Pressure Tanks (can hold 350k):
80 Steel
40 Stonebricks
200 Ironpipes
Normal Storage Tank (can hold 25k)
800 Iron plates
80 Steel
Angels Gas Tank (can hold 125k)
160 Steel
800 Iron plates
160 Stonebricks
160 Ironpipes
Why would anyone get a storage tank mk4 (can hold 100k) when angels gas tank is much cheaper and even better? Not to mention the pressure-tanks.
Also, since the ore-silos are so huge and useful, they should be more pricey.