This gives you a detail list:

SELECT F.[user_id], F.First_Purchase_Date

FROM (

SELECT [user_id],

MIN(dbo.orders.created_date) AS First_Purchase_Date

FROM dbo.orders

WHERE base_price > 0

GROUP BY [user_id]) F

WHERE F.First_Purchase_Date >= DATEADD(DAYOFYEAR, - 1, GETDATE())