In my campaign, the Cleric wanted to create a +1 weapon for the Fighter.
As DM I said: "No problem. Go to the city (tech level 8 in a Judges Guild campaign) and buy the appropriate materials and craft it whenever you wish."
Cleric: "Why can I not just buy the materials here in the village (tech level 4)?"
DM: "Because those materials are not available in the village. Nobody here usually crafts magic items, even the clerics in the local temple. And even if they did, they would still order or acquire the materials from the city."
As DM I said: "No problem. Go to the city (tech level 8 in a Judges Guild campaign) and buy the appropriate materials and craft it whenever you wish."
Cleric: "Why can I not just buy the materials here in the village (tech level 4)?"
DM: "Because those materials are not available in the village. Nobody here usually crafts magic items, even the clerics in the local temple. And even if they did, they would still order or acquire the materials from the city."