How to design API so it would fit REST conventions and Ember.js way?

Would be a good practice to merge all properties of Item:

{id: 1, priceId:1, property1:0} with its corresponding Price {id:1,seasonalPrice:123,regularPrice:120} into:

{id:1,property1:0, price:{seasonalPrice:123,regularPrice:120}}.

Ember most likely can handle linking and combining(merging) two jsons that arrive as two promises from backend REST API into one model. What is the best approach?