diff --git a/Aux-AddOn.toc b/Aux-AddOn.toc
index 1323378..2d81644 100644
--- a/Aux-AddOn.toc
+++ b/Aux-AddOn.toc
@@ -1,7 +1,7 @@
 ## Interface: 11200
 ## Title: Aux
-## SavedVariablesPerCharacter: aux_recent_searches, aux_favorite_searches
-## SavedVariables: aux_datasets, aux_items, aux_auctionable_items, aux_post_mode, aux_price_per_unit, aux_tooltip_daily, aux_tooltip_disenchant_value, aux_tooltip_disenchant_distribution, aux_tooltip_disenchant_source
+## SavedVariablesPerCharacter: aux_recent_searches, aux_favorite_searches, aux_post_mode, aux_price_per_unit, aux_tooltip_daily, aux_tooltip_disenchant_value, aux_tooltip_disenchant_distribution, aux_tooltip_disenchant_source
+## SavedVariables: aux_datasets, aux_items, aux_auctionable_items, aux_merchant_buy, aux_merchant_sell
 
 slash.lua
 core.xml
diff --git a/core.lua b/core.lua
index fc6bdd6..108d986 100644
--- a/core.lua
+++ b/core.lua
@@ -47,6 +47,7 @@ function Aux.on_load()
         end)
     end
 
+    Aux.merchant.on_load()
     Aux.item_cache.on_load()
     Aux.persistence.on_load()
     Aux.tooltip.on_load()
@@ -98,7 +99,8 @@ function Aux.on_addon_loaded()
                 for i=1,reagent_count do
                     local item_id, suffix_id = Aux.info.parse_hyperlink(GetCraftReagentItemLink(id, i))
                     local count = ({GetCraftReagentInfo(id, i)})[3]
-                    local value = Aux.history.value(item_id..':'..suffix_id)
+                    local _, price, unlimited = Aux.merchant.info(item_id)
+                    local value = price and unlimited and price or Aux.history.value(item_id..':'..suffix_id)
                     if not value then
                         total_cost = nil
                         break
@@ -124,7 +126,8 @@ function Aux.on_addon_loaded()
                 for i=1,reagent_count do
                     local item_id, suffix_id = Aux.info.parse_hyperlink(GetTradeSkillReagentItemLink(id, i))
                     local count = ({GetTradeSkillReagentInfo(id, i)})[3]
-                    local value = Aux.history.value(item_id..':'..suffix_id)
+                    local _, price, unlimited = Aux.merchant.info(item_id)
+                    local value = price and unlimited and price or Aux.history.value(item_id..':'..suffix_id)
                     if not value then
                         total_cost = nil
                         break
diff --git a/merchant.lua b/merchant.lua
index cbcbd5b..1710b26 100644
--- a/merchant.lua
+++ b/merchant.lua
@@ -1,18 +1,27 @@
 local private, public = {}, {}
 Aux.merchant = public
 
-local sell_data = {}
-local buy_data = {}
+aux_merchant_buy, aux_merchant_sell = {}, {}
 
 function public.on_load()
     Aux.control.event_listener('MERCHANT_SHOW', private.scan_merchant).start()
 end
 
+function public.info(item_id)
+    local unit_price, unlimited
+    if aux_merchant_buy[item_id] then
+        local buy_fields = Aux.util.split(aux_merchant_buy[item_id], '#')
+        unit_price, unlimited = tonumber(buy_fields[1]), not not tonumber(buy_fields[2])
+    end
+
+    return aux_merchant_sell[item_id], unit_price, unlimited
+end
+
 function private.scan_merchant()
     Aux.util.loop_inventory(function(bag, slot)
         local item_info = Aux.info.container_item(bag, slot)
         if item_info then
-            sell_data[item_info.item_id] = item_info.tooltip.money / item_info.aux_quantity
+            aux_merchant_sell[item_info.item_id] = item_info.tooltip.money / item_info.aux_quantity
         end
     end)
 
@@ -21,6 +30,29 @@ function private.scan_merchant()
     for i=1,merchant_item_count do
         local item_id = Aux.info.parse_hyperlink(GetMerchantItemLink(i))
         local _, _, price, count, stock = GetMerchantItemInfo(i)
-        buy_data[item_id] = Aux.util.join({price / count, stock}, '#')
+        local new_unit_price, new_unlimited = price / count, Aux.persistence.blizzard_boolean(stock == -1)
+        if aux_merchant_buy[item_id] then
+            local fields = Aux.util.split(aux_merchant_buy[item_id], '#')
+            local old_unit_price, old_unlimited = tonumber(fields[1]), tonumber(fields[2])
+
+            local unit_price
+            if old_unlimited and not new_unlimited then
+                unit_price = old_unit_price
+            elseif new_unlimited and not old_unlimited then
+                unit_price = new_unit_price
+            else
+                unit_price = min(old_unit_price, new_unit_price)
+            end
+
+            aux_merchant_buy[item_id] = Aux.util.join({
+                unit_price,
+                old_unlimited or new_unlimited,
+            }, '#')
+        else
+            aux_merchant_buy[item_id] = Aux.util.join({
+                new_unit_price,
+                new_unlimited,
+            }, '#')
+        end
     end
 end
\ No newline at end of file
diff --git a/persistence.lua b/persistence.lua
index 2c022e9..aadfd2c 100644
--- a/persistence.lua
+++ b/persistence.lua
@@ -12,6 +12,10 @@ function private.get_dataset_key()
 	return private.realm..'|'..private.faction
 end
 
+function public.blizzard_boolean(bool)
+    return bool and 1 or nil
+end
+
 function public.load_dataset()
     local dataset_key = private.get_dataset_key()
     aux_datasets[dataset_key] = aux_datasets[dataset_key] or {}
diff --git a/slash.lua b/slash.lua
index 27b2335..266cd25 100644
--- a/slash.lua
+++ b/slash.lua
@@ -6,9 +6,15 @@ function SlashCmdList.AUX(parameter)
     elseif parameter == 'clear post' then
         Aux.persistence.load_dataset().post = nil
         Aux.log('Post settings cleared.')
-    elseif parameter == 'clear' then
+    elseif parameter == 'clear datasets' then
         aux_datasets = {}
-        Aux.log('Database cleared.')
+        Aux.log('Datasets cleared.')
+    elseif parameter == 'clear merchant buy' then
+        aux_merchant_buy = {}
+        Aux.log('Merchant buy prices cleared.')
+    elseif parameter == 'clear merchant sell' then
+        aux_merchant_sell = {}
+        Aux.log('Merchant sell prices cleared.')
     elseif parameter == 'clear item cache' then
         aux_items = {}
         aux_auctionable_items = {}