Revert "Remove listprice code and read price adjustments from database (#56)" (#57)

This reverts commit cdcefda954.

api/lib/prices.py

@@ -1,10 +1,15 @@
 # coding=UTF-8
 """ Price formulas """
-from api.lib.utils import round_half_up
+import yaml
+from api.lib.utils import lru_with_ttl, round_half_up
 from api.models.external_print_product import get_external_print_product
-from api.models.price_adjustments import get_price_adjustment
 
 
+@lru_with_ttl(ttl_seconds=3600)
+def get_adjustment_config():
+    with open("api/resources/price-adjustments.yaml") as f:
+        return yaml.load(f, Loader=yaml.FullLoader)
+
 def wallpaper_m2_price(
     material,
     market,
@@ -29,8 +34,12 @@ def wallpaper_m2_price(
     price *= market.exchange_rate
     price *= market.price_adjustments
 
+    adjustment_config = get_adjustment_config()
+
     inquiry_or_product_key = "product" if inquiry is None else "inquiry"
-    price *= get_price_adjustment(market.name, material.name, inquiry_or_product_key)
+
+    adj_value = adjustment_config.get(material.name).get(inquiry_or_product_key).get(market.name, 1.0)
+    price *= adj_value
 
     if inc_vat:
         price *= market.vat