Trading Alolan forms and Castforms
1. If I have previously caught Normal/Sunny/Rainy Castform but never caught Snowy Castform, will I have to pay more stardust than usual to trade for Snowy Castform?
2. If a species has an Alolan form and I have caught the Kantonian form but not the Alolan form, will I have to pay more stardust than usual to trade for the Alolan form?
Bonus question: What do you think the answer will be for species in future generations with multiple forms, such as Rotom?
Answers
The Alolan forms, weather forms of Castform, and Unown letters are coded separately in the Pokedex; that is, there are empty spaces for forms you haven't yet caught. It doesn't give you the 500 XP bonus for catching an alternate form, but they do count as 'new'. Similarly, Alolan Ratatta and Exeggutor are silhouettes on the radar until you catch them.