A few points to make:
As Kuurus says the prices may have heard of are for ULT potions (50 sips)+
Go to a lower skilled loremaster get cheaper potions (evry sip less than 50 10 GP less).
Similarly with items 250 charges is MAX, tkae less charges the pric is relatively that much cheaper.
These changes are as much as anything to bring back perspective, as to the relswing east value of the potions/items/runes in question.
I suggest you speak to a Loremaster to see how pricing structure works.
Regarding commods to make these items, City still controll the commods which loremaster will buy to ply their trade. Doesnt anyone realise how this system allows younger Loremasters to feel of value and still allows city economies to indirectly benefit.